TS 

38.0 


IRLF 


HANDBOOK 


ON  - 


GIFT  OF 


Steel  Hammer.    Used  for  general  forging,  such  as  billets,  shafts, 
special  shapes,  etc. 


SHOP  HANDBOOK 


ON 


ALLOY  STEELS 


A  technical  subject 

treated  in  a 
non-technical  way 


BY 


G.  VAN  DYKE 

Manager,  Special  Steel  Department 
Joseph  T.  Ryerson  &  Son 


JOSEPH  T.  RYERSON  &  SON 

ESTABLISHED  1842         INCORPORATED   1888 

IRON         STEEL         MACHINERY 

CHICAGO          ST.  LOUIS          DETROIT          BUFFALO          NEW  YORK 


COPTRIOHT,  1921 

JOSEPH  T.  RTEBSON  A  SON 
CHICAGO 


TABLE  OF  CONTENTS 


Detailed  index  will  be  found  on  the 
following  page 


CHAPTER  PAGE 

I  Quality  (Analysis  not  the  only  factor) ...  12 

II  Method  of  Manufacture 15 

III  Elements  and  the  Part  They  Play 16 

IV  How  to  Buy  and  Select  Alloy  Steels 21 

V  Shop  Equipment 28 

VI  Furnaces 29 

VII  Quenching  Equipment 33 

VIII  Heat  Measurement .  „ ..... V !7!, . .  1 36 

IX  Heating ..£.- ;.-.;...-..-. 39 

X  Cooling  and  Quenching. . , 43 

XI  Drawing 48 

XII  Annealing .^. . '.'. . ','*. 50 

XIII  Testing  Heat  Treated  Steel .  .^.  ^  .  „  . . .  54 

XIV  Case  Hardening  or  Carbonizing 58 

XV  General  Remarks .  .66 


[7] 


494487 


DETAILED  INDEX 


Alloy  Steel 


PAGE 


Untreated  ...................  25 

Low  Carbon  .................  26 

High  Carbon  .................  26 

Analyses  01  Alloy 


Annealing  ...............  50,  61,  52 

Overheated  Steel  .............  53 

Axles  .........................  21 

Ball  Bearing  Steel  .....    ,  .......  19 


Lead,  Salt,  Oil 30 

Barium  Chloride 31 

Bolts 21.  23,  26 

Brinell  Hardness 55 

Buying  Alloy  Steels 12,  13,  66 

Calcium  Chloride...  ..  31 

Cams 21 

Carbon 

Effect  of 16 

Steels 16,  17,  93 

Crucible  Machinery 16 

Carbonizing 58 

Case  Hardening 58 

Mixtures 69,  60 

Boxes 60 

Temperature 59, 61 

Furnaces 61 

Depth  of 59,  61,  62 

Heat  Treatment  Following 62 

Formulae 92 

Experiments 63 

Packing 64,  71 

Common  Steel 71 

Chromium 

Effectof 19,20 

Amount  In  Different  Steels 19 

Nickel 19,95 

Vanadium 19,  94 

Connecting  Rods 21,  27 

Cooling 43 

Rate  of 44,45 

Core  Examination 65 

Cost 12,  15 

Countershafts 27 

Cracking,  Cause  of 69,  70 

Crankshafts 21,  27 

Critical  Temperature 17,  43,  44 

Range 43,  44 

Crucible  Process ; 15 

Crystallization 26 

Cyanide  of  Potassium 31 

Cyanide  Hardening 64 

D 

Dead  Soft  Steel 16 

Drawing 48,  49,  70 

E 

Electric  Furnace  Process 15 

Elements,  Refer  under  Names. 
Expansion 39,  40 

Fatigue 26 

Forging  Alloy  Steels 72 

Fuel,  Amount  Used 41 

Furnaces 29 

Atmosphere 41,  50,  72 

Constant  Temperature 40 

Using  Two  In  Heat  Treatment  40, 41 
Temperature,  Excessive 70 

Gears 21,27 

Hardening  Tool  Steel 12 

Hardness 17,  55 

Relation  to  Strength 56,  57 

Heating 39,  67 

Effect  of  Rapid 69 


H — Continued  PAGE 

Heat  Treater,  Duty  of 38 

Heat  Treatment,  Records 68 

Heat  Measurement 36,  37 

High  Speed  Steel 19 

Hot  Working  Die  Steel 19 

Initial  Cost ..  13 

Inspection 12 

J 

Jack  Shaft 21 

L 

Lathe  Spindles 27 

Lead  Bath 30 

M 
Machinery  Steel 16 

Tools 27 

Manganese,  Effect  of 18 

Steel 18,95 

Manufacture,  Method  of 12,  15 

Mild  Steel 16 

Nickel,  Effectof...  ..  20 

Nickel  Steels 20.  93 

Nuts 21,  23 


Oil  Bath  (for  Heating) 30,  31 

Open  Hearth  Process 15 

Ordering 15,  21 

P 

Packing  for  Case  Hardening 64 

Phosphorus,  Effect  of 17 

Physical  Properties,  Definitions  of  79 
Properties  of  Alloy  Steels. .  .22,  26,  27 
Pyrometer 

Electric 36,37 

Optical 36.37 

Checking 37,  73 

Q 

Quality 12,  15 

Quenching 

Equipment 33 

What  Happens 33 

Medium 34,  45 

Tanks 34 

Points  to  Watch 34,  45,  46,  47 

Medium,  Agitation  of 46 

Rising  and  Falling  Temperature.  68 
R 

Roller  Bearing  Steel 19 

Rolling 12 

S 

S.  A.  E.  Specifications 

22,  23,  74,  93,  94,  95 

Salt  Bath 30,  31 

Scleroscope  Hardness 55 

Selection  of  Alloy  Steels 21 

Shop  Equipment 28 

Silicon,  Effect  of 18 

Size,  Effect  of 45 

Sodium  Chloride 31 

Spring  Clips 26 

Substitutions 24,  25 

Sulphur,  Effect  of .  . 18 

Surface  Defects 12 

T 

Tensile  Strength 54,  55,  79 

Testing 54 

Testing  Machines 54 

Tool  Steel 12 

U 
Uniform  Furnace  Temperature ...  30 

W 
Warehouse  Stocks 21 


[8] 


INTRODUCTION 

THE  alloy  steel  industry  has  shown  remarkable 
growth  and  development  during  the  last 
five  or  six  years. 

The  World  War  and  the  automobile  industry  have 
been  the  principal  factors  in  this  development. 

The  advent  of  the  automobile  made  it  necessary 
to  produce  steels  having  great  strength  and  also  a 
ductility  or  toughness  far  beyond  that  of  the  better 
known  carbon  steels.  Alloy  steel  research  work  has 
therefore  been  carried  on  by  certain  steel  manu- 
facturers and  also  by  the  members  of  the  automobile 
industry,  and  as  a  consequence  remarkable  results 
have  been  obtained  in  a  short  time. 

To  the  steel  using  fraternity  in  general  the  highly 
successful  nature  of  the  results  of  this  experimental 
work  in  alloy  steels  has  been  fairly  well  known,  but 
coupled  with  this  knowledge  has  too  often  come  the 
belief  that  the  use  of  alloy  steel  involved  the  handling 
of  various  mysterious  and  secret  processes  which 
were  summed  up  under  the  general  heading  of  "heat 
treatment." 

As  a  result,  while  many  people  recognized  the 
decided  advantages  of  alloy  steels,  they  hesitated  to 
use  them,  believing  that  satisfactory  results  could 
only  be  obtained  by  the  maintenance  of  large, 
expensive  laboratories  coupled  with  the  services  of 
highly  trained  technical  men. 

While  more  general  use  of  alloy  steels  had  been 
making  itself  apparent  prior  to  the  great  war, 
progress  has  been  extremely  slow.  Coupled  with 
the  entrance  of  our  country  into  the  conflict  came 
the  heavy  demand  for  automobile  trucks,  ordnance, 
armor  plate,  steel  helmets,  and  the  many  other  army 

[9] 


JOSEPH         T.       ^RYERSON         &         SON 

and  navy  requirements  which  could  only  be  manu- 
factured successfully  by  the  use  of  the  highest  types 
and  best  grades  of  alloy  steels,  and  then  only  when 
these  steels  were  subjected  to  careful  and  accurate 
heat  treatment. 

Our  government  arsenals,  of  course,  have  long 
been  familiar  with  the  use  of  alloy  steels  in  the 
manufacture  of  guns,  armor  piercing  shells,  rifle 
barrels,  and  other  naval  and  military  equipment,  but 
their  productive  capacity  was  naturally  too  small 
to  turn  out  the  large  quantity  of  material  necessary 
to  meet  the  emergency.  To  supplement  the  manu- 
facturing facilities  of  the  few  highly  specialized  shops, 
it  was  necessary  for  the  manufacturers  of  the  country 
in  general  to  take  up  the  production  of  government 
material,  and  thus  it  followed  that  many  shops  that 
had  never  before  used  alloy  steels  found  themselves 
buying,  machining,  and  heat  treating  these  special 
steels,  and  found  also  that  they  could  obtain  entirely 
satisfactory  results. 

The  present  situation  is  such  that  alloy  steel  parts 
are  in  demand  by  all  industries  and  that  these  steels 
are  coming  into  more  general  use  every  day. 

Representative  steel-service  plants  of  the  country 
are  carrying  alloy  steel  bars  in  stock  the  same  as 
any  other  standard  steel  product. 

Alloy  steels  have  come  to  stay,  and  every  day 
finds  some  heavy  part  which  had  previously  been 
made  of  carbon  steel  replaced  with  a  lighter,  tougher, 
and  better  part  made  from  one  of  the  various  com- 
mercial grades  of  3J^  per  cent  nickel,  chrome  nickel, 
or  other  special  steels. 

It  is  the  purpose  of  this  book  to  avoid  all  tech- 
nicalities and  to  condense  in  a  small  space  sufficient 
information  to  enable  the  average  shop  superin- 
tendent to  take  hold  of  a  special  job,  select  and  buy 
the  steel  for  it,  and  finally  to  give  it  such  heat 
treatment  as  will  produce  the  desired  result. 

[10] 


ALLOY 


STEEL 


I     N 


STOCK 


Free  and  generous  exchange  of  views  and  ideas  by 
members  of  the  trade  are  always  of  value  and 
interest. 

The  various  heat  treaters  organizations  about  the 
country  have  done  much  along  this  line,  and  will 
undoubtedly  do  much  more  to  spread  practical 
information  in  the  future. 

During  our  association  with  many  of  the  leaders 
in  the  manufacture  and  use  of  alloy  steel,  and 
membership  in  various  societies  and  associations,  we 
have  built  up  a  fund  of  information,  data  and 
experience  which  of  necessity  can  not  all  be  included 
in  this  small  book,  but  which  is  available  for  all  who 
seek  it. 


[11] 


JOSEPH        T.        RYERSON        &        SON 


CHAPTER  I 

QUALITY 

(Analysis  not  the  only  factor) 

IT  seems  appropriate  at  the  start  to  call  the 
attention  of  the  reader  to  the  matter  of  quality 
of  the  alloy  steel  which  he  may  contemplate 
buying  and  using. 

Practically  all  users  of  alloy  steels  have  been  in 
the  past,  or  are  at  present,  users  of  tool  steels,  and 
they  will  therefore  understand  that  chemical  anal- 
ysis is  far  from  being  the  only  factor  governing  the 
ultimate  result  to  be  obtained  from  the  use  of  any 
steel. 

All  tool  and  die  makers  know  the  difference  be- 
tween a  piece  of  common  grade  tool  steel  and  a 
piece  of  special  grade  tool  steel,  even  if  the  carbon 
content  of  each  is  exactly  the  same  and  general 
analysis  very  close  in  both  grades.  The  real  differ- 
ence in  the  two  steels  mentioned  is  in  the  method 
of  manufacture.  This  is  governed  by  such  factors 
as  the  kind  of  raw  material  used,  the  method  of 
melting  and  casting,  the  amount  of  steel  cut  off  the 
end  of  the  original  ingot,  the  amount  of  rolling  or 
hammering  done  and  the  care  used  in  annealing  and 
inspecting  the  finished  bars. 

A  mild  steel  bar  is  in  the  majority  of  cases  used 
just  as  it  is  received  from  the  mill.  If,  therefore,  it 
satisfactorily  passes  mill  inspection  for  size  and 
freedom  from  surface  defects  it  will  generally  be 
satisfactory  to  the  ultimate  consumer.  Tool  steel, 
on  the  other  hand,  as  received  from  the  mill  has 
only  started  its  journey,  and  it  may  be  said  that  its 

[12] 


ALLOY  STEEL  IN  STOCK 

manufacture  is  not  completed  until  it  has  passed 
through  its  final  process,  which  consists  of  heat 
treatment  or  hardening. 

Inasmuch  as  practically  all  of  the  alloy  steel 
purchased  is  subject  to  heat  treatment  before  use, 
it  would  therefore  seem 
that  alloy  steels,  like  tool 
steels,  cannot  be  judged 
entirely  by  their  analysis. 
It  is  well  known  to  alloy 
steel  manufacturers  that 
the  ability  of  these  steels 
to  withstand  the  severe 
stresses  put  upon  them  by  heat  treatment  depends 
not  only  on  their  analysis  or  composition,  but  also 
on  the  various  processes  through  which  they  have 
passed  during  the  period  of  manufacture  at  the  mill. 

For  these  reasons  it  should  be  clearly  remembered 
that  in  purchasing  alloy  steels  the  reliability  and 
reputation  of  the  manufacturer  should  be  given 
full  consideration.  The  element  of  original  cost 
must  not  be  overlooked  in  order  to  secure  econom- 
ical production;  but  it  is  equally  important  to 
remember  that  each  finished  part  represents  just  so 
much  money  spent  for  machine  work  and  heat  treat- 
ing, and  in  most  cases  a  cent  or  a  fraction  of  a  cent 
per  pound  in  the  initial  cost  is  a  very  small  factor 
when  compared  with  the  money  expended  on 
machine  work,  heat  treating,  freight,  and  other 
elements  of  the  total  cost. 


[13] 


JOSEPH        T.        RYERSON        &        SON 


Casting.    Molten  steel  being  poured  from  ladle  into  molds. 

[14] 


ALLOY  STEEL  IN  STOCK 


CHAPTER   II 

METHOD  OF  MANUFACTURE 


AXOY  steels  are  being  manufactured  by  the 
following  processes  : 

Crucible  Process. 
Open  Hearth  Process. 
Electric  Furnace  Process. 

The  crucible  process,  owing  to  extreme  cost,  is  not 
used  for  heavy  tonnage  production,  and  need  not 
be  considered  by  the  average  manufacturer,  it  being 
impossible  to  produce  a  strictly  crucible  melted  alloy 
steel  at  a  price  sufficiently  low  to  enable  the  user  to 
compete  with  others  who  are  using  steel  made  by 
one  of  the  other  methods. 

A  discussion  of  the  relative  merits  of  the  open 
hearth  process  and  electric  furnace  process  would 
cover  far  more  space  than  is  permitted  in  this  book 
and  would  also  of  necessity  be  extremely  technical. 

Steel  of  the  very  best  quality  can  be  made  by 
either  the  electric  furnace  or  the  open  hearth  process, 
and  it  is  perhaps  safe  to  assume  that  the  ultimate 
quality  depends  more  on  the  selection  of  raw  material  , 
care  used  in  manufacturing,  and  knowledge  and 
experience  of  the  maker  rather  than  the  particular 
method  which  he  follows  in  making  the  steel. 

After  all,  the  best  solution  of  this  problem  for  the 
average  shop  is  to  buy  material  from  an  entirely 
reliable  source  of  supply,  specifying  the  purpose  for 
which  the  material  is  to  be  used  and  leaving  it  to  the 
sellers  to  furnish  steel  in  which  they  have  confidence 
and  on  which  they  are  willing  to  stake  their  reputa- 
tion. 

[15] 


JOSEPH        T.         RYERSON         &        SON 


CHAPTER  III 

ELEMENTS,  AND  THE  PART  THEY  PLAY 

IN  this  chapter  we  will  endeavor  briefly  to  outline 
the  various  properties  imparted  to  steel  by  the 
addition  of  the  most  commonly  used  metals, 
such  as  nickel,  chromium  and  vanadium,  also  the 
effect  of  the  presence  of  carbon,  manganese,  silicon, 
phosphorus,  and  sulphur. 

CARBON 

One  of  the  most  important  elements  in  any  steel 
is  carbon.  The  effect  not  only  makes  itself  apparent 
in  the  steel  itself  and  the  results  obtained  from  its 
use,  but  is  also  of  primary  importance  in  the  deter- 
mination of  the  correct  heat  treatment. 

In  straight  carbon  steels,  that  is,  steels  composed 
of  iron,  carbon,  and  small  percentages  of  such  ele- 
ments   as    manganese,    silicon,    phosphorus,    and 
sulphur,  the  varying  amounts  of  carbon  produce 
steels  which  may  be  roughly  listed  as  follows: 
Dead  soft  steel,  carbon  not  over  0.10  per  cent. 
Mild  steel,  carbon  not  over  0.25  per  cent. 
Machinery  steel,  carbon  0.25  to  0.40  per  cent. 
Crucible  machinery  steel  (not  necessarily  a 
crucible  product),  carbon  0.40  to  0.60  per 
cent. 
Low  carbon  tool  steel,  carbon  0.60  to  0.75 

per  cent. 

Carbon  over  0.75  per  cent  is  used  in  various  grades 
of  tool  steel,  sometimes  running  as  high  as  2  per 
cent.  The  most  common  range  of  carbon  in  tool 
steel  is  0.75  per  cent  to  1.20  per  cent. 

[16] 


ALLOY  STEEL  IN  STOCK 

From  these  figures  it  will  be  readily  understood 
that  the  greater  the  amount  of  carbon  used  in  steel 
the  harder  the  steel  becomes.  This  is  true  for  steel 
either  in  the  annealed  condition,  the  natural  or 
untreated  condition,  or  the  heat  treated  or  tempered 
condition. 

Straight  carbon  steel  which  is  cooled  rapidly  from 
above  its  critical  point  No.  1  (this  term  is  explained 
on  page  43)  begins  to  show  an  increased  hardness 
when  the  carbon  content  is  over  0.25  per  cent.  The 
amount  of  hardening,  while  increasing  with  greater 
carbon  content,  does  not  tend  to  produce  any  great 
degree  of  brittleness  until  the  carbon  content  has 
reached  about  0.50  per  cent. 

When  steel  containing  more  than  about  0.50  per 
cent  carbon  is  suddenly  cooled  from  above  its 
critical  temperature,  it  becomes  intensely  hard  and 
also  develops  extreme  brittleness.  Therefore,  for 
the  great  majority  of  purposes,  alloy  steels  do  not 
contain  much  more  than  about  0.45  per  cent  carbon. 
The  reason  for  this  is  that  alloy  steels  are  principally 
used  where  great  strength,  toughness,  and  freedom 
from  brittleness  are  required. 

PHOSPHORUS 

In  practically  all  steels  the  presence  of  phos- 
phorus may  be  considered  a  detrimental  impurity. 
The  great  danger  of  high  phosphorus  content  is  that 
it  renders  a  steel  liable  to  fracture  when  subjected  to 
intense  vibration  or  sudden  shock.  High  phos- 
phorus does  not  seem  to  give  any  particular  trouble 
during  the  course  of  manufacture,  and  high  phos- 
phorus steel  can  be  successfully  worked  as  long  as  it 
is  at  a  relatively  high  temperature. 

From  this  explanation  it  is  obvious  that  alloy  steels 
must  not  contain  excessive  phosphorus.  The  gen- 
erally accepted  maximum  limit  is  in  the  neighbor- 
hood of  0.04  per  cent  for  commercial  alloy  steels. 

[17] 


JOSEPH         T.         RYERSON         &         SON 

In  good  tool  steel  0.025  per  cent  is  about  the  per- 
missible maximum. 

SULPHUR 

Sulphur  may  be  considered  an  undesirable 
impurity  in  all  steels,  but  its  effect  is  more  or  less  tho 
opposite  of  that  produced  by  phosphorus,  inasmuch 
as  steel  containing  excessive  sulphur  develops 
cracks,  flaws  and  weaknesses  when  worked  hot. 
The  detrimental  effect  is  nevertheless  present  in  cold 
steel,  and  for  this  reason  it  is  not  usual  to  permit  a 
percentage  of  sulphur  exceeding  .045  per  cent. 

MANGANESE 

Manganese  is  present  in  all  steels,  and,  when 
added  in  relatively  large  proportions,  produ 
special  steel  with  properties  entirely  different  from 
those  of  any  other  known  analysis.  This  steel  is 
known  as  manganese  steel  and  may  contain  as  much 
as  14  per  cent  to  15  per  cent  of  manganese. 

Manganese  steels  are  not  in  the  class  of  material 
to  which  this  book  particularly  refers,  and  no 
further  mention  will,  therefore,  be  made  of  them. 

When  present  in  small  quantities  such  as  0.25  per 
cent  to  0.80  per  cent,  manganese  serves  as  a  cleanser 
or  purifier  of  the  steel.  This  action  is  brought 
about  by  the  manganese  forming  a  chemical  union 
with  the  dissolved  oxygen  which  is  present  in  the 
steel,  thus  forming  an  oxide  of  manganese  which  is 
carried  off  in  the  slag.  It  has  also  been  found  that 
in  steels  where  the  phosphorus  and  sulphur  might 
tend  to  produce  a  rather  coarse  grain  the  presence 
of  manganese  tends  to  reduce  this  grain  to  a  more 
normal  and  desirable  size. 


SILICON 

When  present  in  small  quantities  silicon  has  very 
uch  the  same  effect  as  similar  percentages  of 


is 


ALLOY  STEEL  IN  STOCK 

manganese.  When  present  in  larger  quantities 
silicon,  like  manganese,  produces  steels  of  unique 
Characteristics,  the  principal  among  these  being  the 
effect  on  the  magnetic  properties  of  the  steel. 

CHROMIUM 

This  is,  perhaps,  one  of  the  most  important  ele- 
ments to  be  considered  from  the  standpoint  of  alloy 
steels,  and  it  is  used  in  the  production  of  many 
classes  of  material,  among  which  may  be  mentioned 
high  speed  steels,  certain  grades  of  water  hardening 
tool  steels,  hot  working  die  steels,  ball  and  roller 
bearing  steels,  chrome  nickel  steels,  chrome  vana- 
dium steels,  etc. 

Chromium  has  in  general  the  effect  of  producing 
hardness  in  properly  treated  steels,  and  when  added 
in  the  correct  proportions  and  in  suitable  relation  to 
the  balance  of  the  analysis,  takes  the  place  of  a 
certain  portion  of  the  carbon  in  producing  a  harden- 
ing and  strengthening  effect. 

The  amounts  of  chromium  used  in  different  classes 
of  steel  vary  widely,  although  the  following  list  will 
give  an  approximate  idea  of  the  more  generally 
accepted  percentages: 

Kind  of  Steel  Percentage  of  Chromium. 

Chrome  Nickel  Steels |W3|  «<^>  ..  .0.35  to  1 . 25 

Ball  and  Roller  Bearing  Steels 0.80  to  1.25 

Hot  Working  Die  Steels 3.00  to  4.50 

Chrome  Vanadium  Steels 0 . 75  to  1 . 25 

Certain  Water  Hardening  Tool  Steels . .  0 . 20  to  0 . 50 
High  Speed  Steel 3.00  to  5.00 

The  presence  of  chromium  having,  as  before  men- 
tioned, a  somewhat  similar  effect  to  carbon  in  pro- 
ducing hardness  under  heat  treatment,  it  is  very 
essential  that  the  percentage  of  chromium  be  known 
and  given  full  consideration  when  any  heat  treat- 
ment formula  is  being  developed. 

[19] 


JOSEPH        T.         RYERSON        &        SON 

Chromium  increases  the  susceptibility  of  steel  to 
heat  treatment,  and  it  also  has  the  property  of 
carrying  the  hardness  produced  by  quenching  to  a 
greater  depth  so  that  steels  of  a  fairly  high  chro- 
mium content  after  quenching  will,  in  medium  sized 
sections,  be  found  to  have  hardened  all  the  way 
through  to  the  center.  When  present  in  rather  large 
proportions,  such  as  are  found  in  hot  working  steels, 
chromium  enables  the  steel  to  retain  its  hardness 
at  relatively  high  temperatures,  and  it  is  this  prop- 
erty that  makes  these  steels  particularly  suitable 
for  gripper  dies  and  other  work  where  the  steel  will 
be  used  at  high  temperatures  and  must  still  retain 
a  reasonable  degree  of  hardness. 

NICKEL 

Nickel  is  the  best  known  of  all  the  elements  used 
in  the  manufacture  of  alloy  steels.  Nickel  steel  was 
one  of  the  first  alloy  steels  generally  used  and  still 
continues  to  be  extremely  popular. 

Various  percentages  of  nickel  have  been  tried,  and 
it  has  been  found  that  for  general  all  round  work 
about  3^  per  cent  nickel  seems  to  give  the  best 
results,  both  in  the  way  of  producing  a  high  tensile 
strength  and  elastic  limit  and  at  the  same  time 
leaving  the  steel  ductile  and  tough. 

The  presence  of  nickel  may  be  said  to  increase  the 
toughness  and  strength  of  the  steel  and  also  to 
increase  its  resistance  to  sudden  shock  and  excessive 
vibration.  Steels  containing  nickel  respond  very 
readily  to  heat  treatment,  so  much  so  that  a  bar  of 
3}/£  per  cent  nickel  steel  containing  0.40  carbon  will 
have  an  elastic  limit  of  about  60,000  pounds  per 
square  inch  in  the  annealed  condition  and  about 
200,000  pounds  per  square  inch  in  the  maximum 
heat  treated  condition. 


[20] 


ALLOY  STEEL  IN  STOCK 


CHAPTER  IV 

HOW  TO  BUY  AND  SELECT 
ALLOY  STEELS 


PERHAPS  one  of  the  most  difficult  problems 
that  must  be  solved  by  the  user  of  alloy  steels 
is  the  selection  of  a  suitable  grade  to  use  for  a 
certain  piece  of  work. 

A  study  of  the  table  on  page  22  (Table  A)  will 
show  that  somewhat  similar  physical  characteristics 
may  be  obtained  from  the  use  of  any  one  of  the  sev- 
eral commercial  grades  of  alloy  steel  mentioned,  and 
the  user  will,  therefore,  perhaps,  be  at  a  loss  to  de- 
cide which  class  of  steel  to  select.  For  this  reason 
we  call  attention  to  the  following. 

There  are  many  elements  which  must  be  taken 
into  consideration  besides  the  actual  physical  prop- 
erties which  may  be  obtained  from  any  one  grade  of 
steel.  Among  these  may  be  mentioned  availability, 
cost,  machine  qualities,  equipment  necessary  for 
heat  treatment,  and  past  experience  of  the  user  in 
handling  the  steel  selected. 

The  largest  warehouse  tonnages  of  alloy  steel  are 
confined  to  the  chrome  nickel  steels,  containing 
about  1  to  1.5  per  cent  nickel  and  .40  to  .75  per  cent 
chromium,  and  the  3}/£  per  cenF nickel  steels  (car- 
bon contents  varying  in  both). 

These  two  alloy  steels  are  suitable  when  properly 
heat  treated  for  the  manufacture  of  such  parts  as 
axles,  jack  shafts,  oil  hardened  and  case  hardened 
gears,  high  duty  bolts  and  nuts,  cams,  crank  shafts, 
connecting  rods,  and  the  thousand  and  one  different 

[21] 


JOSEPH 


R    Y    E    R    S    O    N 


SON 


parts  entering  into  the  manufacture  of  automobiles, 
trucks,  tractors,  and  other  special  machines. 

TABLE  A 

COMPARATIVE  PROPERTIES  OF  ALLOY  STEELS 
The  following  are  the  approximate  physical  prop- 
erties which  may  be  obtained  from  some  of  the  alloy 
steels  under  ideal  conditions  of  heat  treatment. 


GRADE  OF  STEEL 

ELASTIC 
LIMIT 
Lbs.  per  sq. 
inch 

REDACTION 
OP  AREA 
Per  cent  of 
Original  area 

ELONGATION 
Per  cent  in 
2  inch 

C'HKOMK  NICKEL 
S.  A.  E.  3120 
Natural  Condition. 
Heat  Treated..  *.<J 

40,000 
100,000 

65 
50      fa 

30 
20 

CHROME  NICKEL 
S.  A.  E.  3135 
Natural  Condition. 
Heat  Treated  V 

55,000 
120,000 

50 
39 

20 
18 

3J/3  PERCENT  NICKEL 
S.  A.  E.  2320 
Natural  Condition. 
Heat  Treated  

45,000 
130,000 

55 
50 

30 
15 

3^  PERCENT  NICKEL 
8.  A.  E.  2340 
Natural  Condition. 
Heat  Treated  

60,000 
170,000 

50 
45 

18 
15 

The  analysis  ranges  most  commonly  used  in 
chrome  nickel  and  3J/£  per  cent  nickel  steels  are  as 
follows: 

Low  CARBON  CHROME  NICKEL  STEEL 
(S.  A.  B.  Specification  3120) 

Carbon /Ltoi.  tdiri&i .  .0. 15  to  0.25 

Nickel 1.00  to  1.50 

Chromium 0.40  to  0.75 

Manganese 0.50  to  0.80 

Phosphorus  maximum 0 . 04 

Sulphur  maximum 0 . 045 


[22] 


ALLOY        STEEL        IN        STOCK 

HIGH  CARBON  CHROME  NICKEL  STEEL 
(S.  A.  E.  Specification  3135) 

Carbon 0.30  to  0.40 

Nickel 1.00  to  1.50 

Chromium 0.40  to  0.75 

Manganese 0.50  to  0.80 

Phosphorus  maximum 0 . 04 

Sulphur  maximum 0 . 045 

Low  CARBON  3J/2  PER  CENT  NICKEL  STEEL 
(S.  A.  E.  Specification  2320) 

Carbon 0. 15  to  0.25 

Manganese 0.50  to  0.80 

Phosphorus  not  over 0 . 04 

Sulphur  not  over 0 . 045 

Nickel 3.25  to  3.75 

HIGH  CARBON  3J/£  PER  CENT  NICKEL  STEEL 
(S.  A.  E.  Specification  2340) 

Carbon 0.35  to  0.45 

Manganese 0.50  to  0.80 

Phosphorus  not  over 0 . 04 

Sulphur  not  over 0 . 045 

Nickel 3.25  to  3.75 

These  steels  are  available  from  stock  in  practically 
all  sizes  from  %  mcn  to  6  inches  round  with  a  hot 
rolled  finish,  and  can  also  be  secured  in  many  sizes 
with  a  cold  drawn  finish.  The  S.  A.  E.  2320  and 
3120  analyses  steels  are  also  carried  in  cold  drawn 
hexagons  for  the  manufacture  of  high  duty  hexagon 
head  bolts  and  hexagon  nuts. 

This  data  is  given  in  connection  with  the  use  of 
the  previously  mentioned  four  standard  grades  of 
alloy  steel,  owing  to  the  fact  that  these  can  readily 
be  secured  from  stock  sources  in  large  and  small 
quantities, 

[23] 


JOSEPH         T.         RYERSON         &         SON 

It  is  not  always  possible  to  obtain  the  size  or 
quantity  of  steel  needed  in  the  particular  analysis 
desired,  and  we  therefore  attach  a  possible  substi- 
tution list.  A  study  of  this  list  will  show  that  where 
a  certain  analysis  is  specified  one  or  more  of  the 
other  alloy  steels  can  probably  be  used  in  its  place 
with  satisfactory  results.  It  must  not,  of  course, 
be  taken  for  granted  that  this  will  hold  true  in  each 
and  every  case,  and  where  a  doubt  exists  the  matter 
should  be  referred  to  some  authority  on  the  subject. 
In  using  the  substitution  list  it  is  of  the  utmost 
importance  that  the  heat  treatment  of  the  substitute 
steel  be  carefully  considered,  inasmuch 
as  in  all  probability  it  will  not  be  the  same 
as  the  treatment  of  the 
originally  specified  analysis. 


ALLOY 


STEEL  IN 

SUBSTITUTION  LIST 


STOCK 


Steel  Specified 
S.  A.  E.  No. 

Possible  Substitution 
S.  A.  E.  No. 

3120 

2320 

6120 

3130 

2320 
2330 
2335 

3120 
3135 
3140 

6120 
6125 
6130 

3135 

2330 
2335 
2340 

3130 
3140 

6125 
6130 
6135 

3140 

2330 
2335 
2340 

3135 

6130 
6135 

2320 

3120 

6120 

2330 

2320 
2335 
2340 

3130 
3140 

6125 
6130 
6135 

2335 

2330 
2340 

3135 
3140 

6125 
6130 
6135 

2340 

2330 
2335 

3135 
3140 

6130 
6135 

6120 

2320 

3120 

6125 

2330 
2335 

3130 
3140 

6120 
6130 

6130 

2330 
2335 
2340 

3130 
3135 
3140 

6125 
6135 

6135 

2335 
2340 

3135 
3140 

6130 

It  must  be  clearly  remembered  that  in  selecting 
an  alloy  steel  for  any  special  purpose  the  physical 
properties  of  the  steel  in  its  heat  treated  condition 
must  determine  its  use.  Alloy  steels  in  the  untreated 
or  natural  condition  undoubtedly  have  advantages 
over  the  non-alloy  steels,  but  the  advantages  are  not 
sufficient  to  warrant  the  increased  cost.  Another 
factor  in  this  matter  is  that  no  reliance  can  be  placed 
on  the  physical  properties  of  untreated  alloy  steels. 


[25] 


JOSEPH         T.         RYERSON         &         SON 

These  physical  properties  will  vary  widely  in  bars  of 
different  sizes  and  also  in  different  bars  of  the  same 
size.  This  condition  depends  upon  the  amount  of 
work  which  has  been  done  on  the  steel  at  the  mill  and 
also  largely  on  the  final  temperature  of  rolling. 

The  most  readily  procured  alloy  steels  may  be 
roughly  divided  into  two  classes,  the  first  being  of 
low  carbon  content  and  the  second  of  relatively  high 
carbon  content.  These  two  classes  are  naturally 
used  for  widely  divergent  purposes.  In  order  to 
assist  the  prospective  user  we  will  endeavor  to  give 
a  brief  outline  of  the  general  application  of  the  two 
classes  of  material. 

Low  CARBON  ALLOY  STEELS 
The  low  carbon  alloy  steels,  such  as  chrome  nickel 
(S.  A.  E.  3120)  and  3J^  per  cent  nickel  (S.  A.  E. 
2320)  with  a  carbon  range  of  from  .15  to  .25  per  cent, 
are  used  primarily  for  parts  which  are  to  be  case 
hardened.  They  are  also  used  for  certain  struc- 
tural purposes  such  as  spring  clips,  bolts,  and  other 
parts  which  will  be  subjected  to  frequently  alter- 
nating stresses  and  intense  vibration.  When  prop- 
erly heat  treated  these  low  carbon  steels,  though 
not  developing  a  very  high  tensile  and  elastic  limit, 
show  a  very  fine  fibrous  structure  and  one  having 
consequently  great  resistance  to  fatigue,  or  what  is 
commonly  but  erroneously  known  as  crystallization. 
Owing  to  the  ability  of  these  low  carbon  steels  to 
stand  relatively  high  temperatures  without  deteri- 
oration, they  are  particularly  suitable  for  drop 
forging. 

HIGH  CARBON  ALLOY  STEELS 
The  most  popular  and  generally  used  high  carbon 
alloy  steels  have  a  carbon  range  of  from  .30  to  .45 
per  cent  carbon,  and  can  readily  be  obtained  in 
either  chrome  nickel  (S.  A.  E.  3135)  or  3J/2  per  cent 
nickel  (S.  A.  E.  2340)  grades. 

[26] 


ALLOY  STEEL  IN  STOCK 

These  higher  carbon  steels  are  used  in  the  most 
part  for  structural  purposes  where  relatively  high 
elastic  limits  coupled  with  a  reasonable  degree  of 
toughness  are  required. 

The  physical  properties  obtainable  by  heat  treat- 
ment of  high  carbon  alloys  render  them  suitable  for 
the  manufacture  of  such  parts  as  crank  shafts,  con- 
necting rods,  counter  shafts,  rocker  arms,  gears, 
keys,  and  in  fact  all  parts  where  high  physical  prop- 
erties are  necessary. 

It  has  been  found  very  advantageous  to  use  some 
of  these  alloy  steels  in  the  manufacture  of  certain 
parts  of  machine  tools  such  as  lathe  spindles,  milling 
machine  spindles,  and  other  parts  where  the  least 
amount  of  bending  under  severe  stress  would  render 
the  tool  entirely  useless.  By  the  use  of  these  high 
grade  steels  the  weight  of  many  machines  can  be 
materially  lowered  without  in  any  way  impairing 
their  efficiency  or  reducing  their  load  capacity. 

The  higher  carbon  alloys  can  be  successfully  drop 
forged,  although  they  cannot  with  safety  be  raised 
to  as  high  a  temperature  as  the  lower  carbon  series. 

From  the  preceding  remarks  in  this  chapter  the 
reader  will  have  noted  that  the  selection  of  the  cor- 
rect grade  of  alloy  steels  presents  several  more  or 
less  technical  problems,  and  these  problems  are  sup- 
plementary to  the  very  important  question  of  avail- 
ability. In  view  of  these  conditions  we  believe  that 
the  most  satisfactory  method  of  handling  this  prob- 
lem will  be  to  take  the  matter  up  in  detail  with  some 
reliable  source  of  supply.  The  sellers  of  special  alloy 
steels  naturally  have  available  the  services  of  men 
thoroughly  familiar  with  the  various  problems  of 
alloy  steel  procurement  and  use,  and,  therefore, 
although  they  do  not  know  all  that  is  to  be  known, 
they  are  in  a  position  frequently  to  give  advice 
which  will  save  both  time  and  money  for  the  user. 


[27] 


JOSEPH 


R    Y    E    R    S    O    N 


SON 


O 


CHAPTER  V 

SHOP  EQUIPMENT 

NE  of  the  most  important  elements  to  be  con- 
sidered when  undertaking  any  heat  treating 
operation  is  the  matter  of  shop  equipment. 
Primarily  heat  treatment  consists  of  subjecting 
the  parts  to  definite  temperature 
increases  over  and   above   the 
normal    atmospheric    tempera- 
tures during  certain  periods  of 
time,  and  also  subjecting  parts 
to  decreases  in  temperature  from 
various  definite  points  to  the 
normal    atmospheric    tempera- 
ture, also  during  certain  time 
intervals. 

It  will  be  readily  understood 
that   in    order    to    adequately 
single  chamber  Heating     han<*le  this  work  there  are  three 

Furnace.  essentials  to  be  considered : 

First,  some  device  whereby  the  temperature  of  the 
part  may  be  increased  to  a  certain  point  and 
maintained  for  any  desired  length  of  time  at  that 
temperature. 

Second,  some  device  whereby  the  temperature  of  a 
piece  may  be  reduced  from  one  point  to  another 
at  any  desired  rate. 

Third,  some  means  for  definitely  measuring  the 
various  high  and  low  temperatures  which  are  used 
in  this  work. 


28 


ALLOY 


STEEL 


I     N 


STOCK 


CHAPTER  VI 

FURNACES 


THE  device  referred  to  as  the  first  essential  may 
be  one  of  the  numerous  gas,  oil,  or  coal  fired 
furnaces  which  are  on  the  market,  or  may  con- 
sist of  a  molten  lead,  molten  salt,  or  oil  bath.  The 
question  of  furnace  design  is  too  large  a  subject  to 
be  handled  in  this  book,  so  it  will  suffice  to  say  that 
money  spent  in  procuring  a  first  class  furnace  is  well 
invested.  The  selection  of  such  a  furnace  should  be 
undertaken  in  conjunction  with  the  service  depart- 
ments of  one  of  the  reputable  furnace  manufac- 
turers. The  question  of  the  design  is,  of  course, 
dependent  upon  such  factors  as  the  fuel  most 
readily  obtainable,  the  size 
of  work  to  be  handled, 
temperatures  required,  and 
other  shop  factors.  The 
same  remarks  will  also 
apply  in  the  matter  of  the 
selection  of  apparatus  using 
molten  salt,  molten  lead,  or 
hot  oil  for  heating. 

In  general  the  following 
items  should  be  considered 
in  furnace  selection:  The 
size  will,  of  course,  depend 
entirely  on  the  class  of  work 
to  be  done,  and,  while  the  furnace  must  be  of  suffi- 
cient proportions  to  accommodate  the  largest  pieces 
which  are  to  be  heat  treated,  it  must  be  remembered 
that  small  pieces  can  not  be  heated  economically  in 


Double  Chamber  Heating 
Furnace. 


29] 


JOSEPH         T.         RYERSON         &         SON 

a  large  furnace.  It  is  also  well  to  note  that  the 
greatest  economy  in  furnace  operation  is  obtained 
when  it  is  run  at  a  more  or  less  uniform  temperature. 
Every  time  the  furnace  is  heated  through  a  certain 
temperature  range  the  furnace  itself  absorbs  a  large 
amount  of  heat,  and  consequently  when  the  furnace 
is  again  cooled  this  heat  is  lost  and  will  have  done 
no  useful  work  in  the  heat  treatment  process.  In 
many  cases  this  alternate  raising  and  lowering  of  the 
furnace  temperature  is  unavoidable,  but  the  matter 
is  worthy  of  consideration  inasmuch  as  frequently 
the  loss  occasioned  by  this  condition  may  be  elimi- 
nated by  the  use  of  two  or  more  furnaces  which  are 
maintained  at  different  but  uniform  temperatures. 

MOLTEN  LEAD,  SALT,  AND  OIL  BATHS 

MOLTEN  LEAD  BATHS 

For  certain  work  the  molten  lead  or  molten  salt 
bath  is  a  very  desirable  method  of  raising  tem- 
peratures. The  steel  is  protected  from  contact  with 
furnace  gases  which,  if  not  properly  balanced  or 
proportioned,  may  cause  excessive  oxidization.  A 
strong  point  in  its  favor  is  that  it  will  hold  a  very 
accurate  temperature.  Owing  to  the  high  specific 
gravity  of  molten  lead,  steel  will  float  in  it  and  must, 
therefore,  be  held  down. 

It  is  very  important  that  the  lead  used  be  free 
from  impurities,  this  applying  particularly  to  sulphur 
which,  if  present  in  the  bath,  may  be  absorbed  to  a 
certain  extent  by  the  steel.  The  lead  bath  when 
dirty  can  be  cleaned  by  throwing  in  perfectly  dry 
sodium  chloride  (common  salt)  and  stirring,  inas- 
much as  this  will  bring  all  dirt  to  the  surface  where 
it  may  readily  be  removed. 

Where  it  is  found  that  the  lead  adheres  to  the 
surface  of  the  pieces  of  steel,  the  difficulty  can  be 
overcome  by  dipping  the  pieces  in  a  saturated  water 

[30] 


ALLOY 


STEEL 


I     N 


T     O     C     K 


solution  of  potassium  cyanide  prior  to  heat  treat- 
ment. The  pieces  must  be  dipped  cold,  and  the 
solution  allowed  to  dry  on  the  surface  before  they 
are  placed  in  the  lead  bath. 

Heating  in  lead  has  no  influence  on  the  quenching 
temperature  of  quenching  medium,  and  steel  after 
it  is  removed  from  the  lead  bath  is  handled  exactly 
the  same  as  if  it  has  been  heated  in  a  furnace  or  by 
some  other  method. 

Molten  lead  baths  may  be  used  conveniently  for 
temperatures  from  about  700°  Fahr.  to  1600°  Fahr. 

MOLTEN  SALT  BATHS 

In  some  particular  instances  molten  salts,  such 
as  barium  chloride,  cyanide  of  potassium,  mixtures 
of  calcium  chloride  and  sodium  chloride,  and  various 
other  mixtures  seem  to  give  very  satisfactory  results. 
The  molten  salts,  however,  frequently  give  con- 
siderable trouble  by  having  a  chemical  effect  upon 
the  surface  of  the  steel.  It  is  well  known  that  cy- 
anide of  potassium,  for  instance,  will  raise  the  carbon 
content  of  the  surface  of  the  steel  to  a  very  high 
point,  and,  although  this  penetration  is  not  deep 
this  method  is  frequently  used  as  a  quick  and  easy 
means  of  case  hardening.  Other 
salts  cause  erosion  and  pitting 
under  some  conditions;  and, 
therefore,  owing  to  the  many 
problems  that  arise  in  connec- 
tion with  molten  salt  baths,  we 
do  not  particularly  recommend 
their  use. 

OIL  BATHS 

Oil  is  one  of  the  most  useful 
mediums  for  the  heat  treater. 
It  is  employed  both  as  a  heating 
and  cooling  medium.  At  present 
we  will  consider  oil  only  from  MolteLSrnac0er. Lead 


[31 


JOSEPH         T.         RYERSON         &         SON 

the  standpoint  of  heating,  wherein  it  may  be  used 
for  temperatures  up  to  and  including  about  600° 
Fahr.  This  temperature,  of  course,  does  not  have 
any  material  effect  on  untreated  or  annealed  steel, 
but  is  used  to  relieve  the  internal  strains  brought  on 
by  quenching  from  higher  temperatures  and  to 
change  the  physical  properties  of  heat  treated  steel. 
For  this  purpose  an  oil  bath  is  extremely  desirable 
owing  to  the  fact  that  a  steady  uniform  temperature 
can  be  maintained  for  any  desired  length  of  time. 
This  is  an  extremely  difficult  operation  to  carry  out 
in  a  furnace  when  using  such  low  heats. 


[32] 


ALLOY        'STEEL  IN  STOCK 


CHAPTER  VII 

QUENCHING  EQUIPMENT 

T  IT  TE  will  now  consider  the  matter  of  temperature 
\\  reduction,  which  is  listed  in  Chapter  V  under 

the  heading  of  essential  No.  2. 
In  heat  treatment  temperature  reduction  is  the 
second  operation  and  follows  the  initial  heating  of 
the  parts  which  are  going  through  the  process. 

Various  mediums  are  available  for  this  heat  reduc- 
tion or  quenching,  such  as  oil,  water,  brine,  ashes, 
slack  lime,  air,  etc.  Note  that,  in  addition  to  the 
large  number  of  different  quenching  mediums  used, 
these  various  mediums  are  used  at  different  tempera- 
tures, all  this  depending  upon  the  degree  of  cooling 
desired  and  also  the  time  element  or  rate  of  cooling 
necessary  to  give  the  desired  result. 

The   physical   properties   of   heat   treated   steel 
depend  primarily  on  five  factors: 
Fir stt  the  analysis  of  the  steel. 
Second,  the  size  of  the  piece  under  consideration. 
Third,  the  temperature  at  the  time  when  the  tem- 
perature reduction  starts. 
Fourth,  the  rate  at  which  the  temperature  reduction 

takes  place. 

Fifth,  the  temperature  of  the  final  heating  or  drawing. 
Oil  and  water  are  probably  the  most  generally 
used  mediums  for  temperature  reduction  or  quench- 
ing, and  in  the  great  majority  of  cases  these  two 
mediums  are  used  as  nearly  as  possible  at  normal 
atmospheric  temperature.  In  order  to  secure 
uniform  results  it  is  necessary  that  the  temperature 
of  the  quenching  bath  be  kept  as  nearly  constant  as 

[33] 


JOSEPH        T.        RYERSON        &        SON 

possible.  Because  repeated  quenchings  will  raise 
the  temperature  of  the  quenching  medium,  these 
baths,  except  where  used  for  very  intermittent 
service,  are  provided  with  cooling  coils  through 
which  cold  water  is  circulated.  Sometimes  this 
cooling  system  is  modified,  and  the  oil  is  pumped 
from  the  tank  through  an  exterior  coil  which  is 
surrounded  by  cold,  circulating  water. 

Addition  of  salt  to  water  increases  the  specific 
heat  of  the  solution,  and  therefore  produces  a  more 
rapid  cooling  of  the  parts  which  are  quenched  in  it. 
However,  care  must  be  used  to  always  maintain 
about  the  same  proportion  of  salt  in  the  bath  or  a 
non-uniform  quenching  will  result. 

With  certain  steels,  and  where  certain  physical 
properties  are  required,  the  atmosphere  will  form 
a  desirable  quenching  medium,  in  which  case  pieces 
are  merely  removed  from  the  heating  furnace  and 
allowed  to  cool  in  the  air.  This  is  naturally  a  slow 
medium  of  cooling,  and  physical  properties  thus 
obtained  are  consequently  lower  than  those  given 
by  the  same  steel  when  quenched  from  the  same 
temperature  in  such  mediums  as  oil  or  water. 

The  whole  problem  of  quenching  mediums, 
designs  of  quenching  tanks,  and  other  shop  details 
are  of  too  broad  a  scope  to  be  taken  up  in  detail  in 
this  book,  and  should  be  included  in  a  general 
scheme  of  shop  equipment  at  the  time  the  furnace 
installation  is  determined.  The  following  general 
remarks  may,  however,  be  useful. 

Be  sure  that  you  provide  means  of  keeping  your 
quenching   bath   at    constant   temperature.    This 
factor  is  governed  by: 
First,  the  weight  of  steel  being  quenched  in  a  given 

time. 

Second,  the  temperature  of  steel  at  time  of  quenching. 
Third,  the  quantity  of  quenching  medium  provided. 

[34] 


ALLOY 


T    E     E     L 


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STOCK 


Fourth,  the  efficiency  of  system  used  to  cool  the 

quenching  medium. 

It  will  be  well  to  emphasize  the  need  of  a  very 
quick  transfer  of  the  hot  steel  from  the  furnace  to 
the  oil  quenching  tank.  As  soon  as  the  steel  is 
taken  from  the  furnace  it  starts  to  lose  heat,  and 
even  if  the  temperature  of  the  steel  while  in  the 
furnace  is  correct  it  will  have  dropped  too  low  if 
much  time  is  lost  in  making  the  transfer  to  the 
quenching  tank.  For  this  reason  the  quenching 
tanks  should  be  as  near  the  furnaces  as  possible. 


Plate  mill,  consisting  of  top  and  bottom  rolls.    Plates  rolled  on  these  mills 
are  irregular  on  the  edges  and  must  be  sheared  on  all  four  sides. 


[35] 


JOSEPH        T.        RYERSON        &        SON 


CHAPTER  VIII 

HEAT  MEASUREMENT 

THE  matter  of  heat  measurement  has  already 
been  given  as  the  third  essential  in  shop 
equipment  for  heat  treating,  and,  while  this 
matter  has  been  taken  up  as  the  third  element,  it 
must  not  be  considered  as  being  third  in  importance. 

Granted  the  use  of  good  steel  and  high  class 
equipment  for  heating  and  quenching,  neither 
accurate  nor  dependable  results  can  be  obtained 
unless  the  operator  has  a  means  of  determining 
accurately  the  temperatures  of  the  various  furnaces, 
lead  baths,  oil  baths,  etc. 

Temperatures  up  to  600°  Fahr.  can  be  accurately 
measured  by  the  use  of  high  temperature  mercurial 
thermometers,  but  where  the  temperatures  used  are 
in  excess  of  this  figure  it  becomes  necessary  to  use 
some  other  means  of  determination. 

There  are  two  methods  in  common  use  of  measur- 
ing the  higher  temperatures:  (1)  by  the  optical 
pyrometer,  and  (2),  the  thermoelectric  couple. 

The  optical  pyrometer  has  its  application  and  is 
useful  in  many  cases,  but  for  numerous  reasons  the 
thermoelectric  apparatus  is  generally  used. 

Very  briefly,  the  principle  of  the  thermoelectric 
couple  is  as  follows:  When  two  pieces  of  metal  of 
different  composition  are  joined  together  at  both 
ends  so  as  to  form  a  complete  electric  circuit,  a  flow 
of  current  is  produced  when  the  two  junctions  or 
joints  are  at  different  temperatures. 

Provided  that  the  wires  are  of  exactly  uniform 
composition  throughout,  the  difference  in  electro- 

[36] 


ALLOY  STEEL  IN  STOCK 

motive  force,  or  voltage,  is  directly  proportional  to 
the  increase  in  temperature,  and  therefore,  if  a  very 
delicate  voltmeter  or  galvanometer  be  placed  in  the 
circuit,  a  reading  can  be  obtained  which  will  indicate 
the  difference  in  temperature  of  the  two  junctions. 

Selection  of  pyrometer  equipment  must  be 
governed  by  such  factors  as  the  permissible  original 
cost  and  also  shop  conditions  and  -kind  of  work 
which  will  be  undertaken.  These  several  matters 
having  been  determined,  the  pyrometer  equipment 
installation  should  be  turned  over  to  one  of  the 
recognized  and  dependable  pyrometer  manufac- 
turers, all  details  being  left  to  their  experience  and 
co-operation. 

In  connection  with  this  matter,  it  may  be  well  to 
emphasize  the  desirability  of  recording  pyrometers. 
These  instruments  are  provided  with  a  moving 
chart,  on  which  a  line  is  automatically  drawn 
representing  the  furnace  temperature  at  all  times. 
Such  a  recorder  can  be  kept  in  a  locked  box,  thereby 
providing  evidence  as  to  just  how  accurately  the 
furnace  operator  has  followed  his  instructions  in 
reference  to  temperature  and  time. 

Whatever  system  is  installed,  it  must  be  remem- 
bered that  the  pyrometer  is  essentially  a  delicate 
instrument,  and  the  voltages  and  currents  handled 
are  necessarily  extremely  small.  For  these  reasons 
it  is  essential  that  the  couples  be  properly  protected 
from  furnace  gas  action  and  that  they  be  handled 
with  care.  All  contacts  must  be  kept  scrupulously 
clean  and  the  indicating  and  recording  instruments 
so  placed  that  they  are  free  from  excessive  vibration 
and  jar,  such  as  may  be  produced  by  steam  hammers 
or  other  heavy  machines.  Pyrometers  must  be 
accurately  checked  at  fairly  frequent  intervals,  this 
being  best  handled  by  the  service  departments  of 
the  various  pyrometer  manufacturers.  (See  page  73.) 

[37] 


JOSEPH        T.        RYERSON        &        SON 

If  the  pyrometer  equipment  is  given  adequate  care 
and  attention,  readings  of  remarkable  accuracy  can 
be  obtained,  but,  on  the  other  hand,  if  not  properly 
cared  for,  inaccuracies  are  bound  to  develop  and 
trouble  with  heat  treatment  will  surely  follow. 

Heat  treated  alloy  steels  are  used  for  the  most 
vital  parts  of  automobiles,  trucks,  aeroplanes,  and 
other  fast  moving  mechanisms,  and  the  safety  of 
human  lives  depends  on  their  withstanding  the 
severe  stresses  that  are  imposed  upon  them.  Their 
success  in  fulfilling  their  function  depends  more 
largely  on  their  heat  treatment  than  any  other 
factor,  and  it  is,  therefore,  a  duty  of  all  those  doing 
heat  treatment  work  to  see  that  this  work  is  properly 
done  and  that  no  chances  are  taken,  either  with  the 
use  of  inferior  material  or  equipment. 

In  using  the  thermoelectric  pyrometer  to  deter- 
mine the  heat  of  a  piece  of  steel,  it  is  well  to  place 
the  thermo  couple  near  the  steel,  and  by  observation 
of  the  heat  color  it  may  be  readily  seen  whether  the 
thermo  couple  and  the  steel  are  at  the  same  tem- 
perature. This  matter  is  of  importance  inasmuch 
as  no  furnace  will  be  the  same  temperature  at  all 
points,  and,  where  the  thermo  couple  is  distant  from 
the  steel,  the  temperature  which  it  registers  may 
not  be  the  actual  temperature  of  the  steel  being 
heated. 


[38] 


ALLOY 


STEEL 


I     N 


STOCK 


CHAPTER  IX 

HEATING 


IN  another  section  of  this  book  there  are  tables 
giving  the  correct  quenching  temperatures  for 
various  alloy  steels,  together  with  the  drawing 
temperatures  and  the  approximate  physical  prop- 
erties resulting  therefrom.  In  order  that  these  tables 
may  prove  of  the  greatest  possible  value,  it  will  be 
in  order  to  outline  briefly  the  general  principles  to 
be  observed  in  following  the  heat  treatment  formula 
given  in  these  tables,  and 
we  will  therefore  first 
consider  the  matter  of 
heating. 

All  steels  when  heated 
are  subject  to  expansion, 
the  amount  of  expansion 
being  more  or  less  directly 
proportional  to  the  in- 
crease in  temperature .  If 
a  bar  of  steel  is  allowed 
to  remain  in  a  furnace 
which  is  at  a  certain 
temperature,  the  center  Tapping  Blast  Furnace, 

of  the  bar,  or  that  part  of  the  metal  farthest  from 
the  surface,  will  ultimately  reach  approximately  the 
same  temperature  as  the  furnace.  It  will  be  obvious 
from  consideration  of  this  matter,  however,  that  the 
heat  must  pass  by  conduction  from  one  particle  of  the 
steel  to  another,  starting  at  the  outside  and  pene- 
trating inward.  A  certain  amount  of  time  is  there- 
fore required  for  the  steel  to  assume  the  same 


[39] 


JOSEPH         T.         RYERSON         &         SON 

temperature  throughout,  consequently  if  the  bar  is 
placed  in  an  extremely  hot  furnace,  the  outside  will 
for  a  while  be  very  much  hotter  than  the  inside 
portion. 

The  difference  in  expansion  of  the  outside  and 
center  of  a  piece  of  steel,  owing  to  the  difference  in 
temperature,  is  dangerous,  and  to  this  cause  may 
be  frequently  attributed  the  development  of  cracks 
or  checks.  This  condition  is  more  highly  developed 
with  some  steels  than  with  others  on  account  of  the 
difference  of  density  and  heat  conductivity.  High 
speed  steels  and  certain  high  percentage  chromium 
steels  are  particularly  dense,  and  in  such  extreme 
cases  very  rapid  heating  is  almost  sure  to  produce 
disastrous  results.  On  the  other  hand,  low  carbon 
steels  which  contain  no  alloys,  such  as  mild  steel, 
are  more  free  from  danger  in  this  respect. 

As  a  general  rule  it  may  be  stated  that  the  higher 
the  carbon  and  the  greater  the  percentage  of  alloys 
in  a  steel  the  more  care  must  be  used  in  raising  the 
temperature.  There  are  exceptions,  of  course,  to 
this  rule,  but  by  taking  it  as  applying  to  all  cases  no 
harm  will  be  done  and  many  undesirable  results 
may  be  avoided. 

Heating,  therefore,  should  be  done  as  slowly  as  is 
commercially  possible,  and  in  all  cases  the  steel 
must  be  allowed  to  remain  in  the  furnace  for  a 
sufficient  length  of  time  to  insure  absolutely  uniform 
heat  penetration  throughout  all  parts  of  the  bars  or 
pieces. 

Where  a  long  run  of  heat  treatment  is  contem- 
plated it  is  sometimes  advantageous  to  use  two  or 
more  furnaces;  furnace  number  one  may  be  main- 
tained at  a  comparatively  low  temperature  and  used 
solely  for  the  purpose  of  pre-heating  the  steel.  After 
having  reached  the  temperature  of  the  pre-heating 
furnace,  the  pieces  can  then  be  transferred  to  the 
higher  temperature  furnace  and  brought  up  to  the 

140] 


ALLOY  STEEL  IN  STOCK 

ultimate  heat  which  is  required.  This  system  will 
give  quicker  results  and  avoid  the  heat  loss  occa- 
sioned by  alternately  raising  and  lowering  the  tem- 
perature of  the  furnace  itself,  as  well  as  insuring  a 
gradual  rise  in  temperature  of  the  parts  which  are 
being  heat  treated. 

Furnace  atmosphere  is  of  the  utmost  importance, 
and  great  care  should  be  used  in  properly  propor- 
tioning the  relative  amounts  of  fuel  and  air. 

Air  is  composed  of  oxygen  and  nitrogen,  and 
where  an  excess  of  air  is  mixed  with  the  fuel  a  sur- 
plus of  free  oxygen  will  exist  in  the  furnace  atmos- 
phere. Free  oxygen,  when  brought  in  contact  with 
heated  steel,  will  combine  chemically  with  the  iron 
contained  in  the  steel,  forming  iron  oxide  or  scale. 
Oxygen  will  also  combine  readily  with  the  carbon 
in  steel  and  will  thus  change  the  carbon  percentage 
in  the  outside  surface  of  the  bar.  Scaling  and  de- 
carbonizing are,  of  course,  both  undesirable  and  can 
be  practically  eliminated  by  properly  proportioning 
the  mixture  of  fuel  and  air  so  that  there  will  be 
sufficient  fuel  to  use  up  all  the  oxygen  which  is 
being  fed  into  the  furnace. 

The  necessity  of  using  a  slight  excess  of  fuel  has 
already  been  indicated,  but  this  action  must  not  be 
carried  too  far.  Where  large  amounts  of  excess  fuel 
are  used  no  advantage  is  gained  and  waste  will  occur. 


[41 


JOSEPH        T.        RYERSON        &        SON 


[42] 


ALLOY  STEEL  IN  STOCK 


CHAPTER  X 

COOLING  OR  QUENCHING 

HAVING  in  the  previous  chapter  considered 
the  matter  of  raising  the  temperature  of  steel 
for  heat  treatment,  we  will  now  touch  on  the 
matter  of  temperature  reduction,  more  commonly 
called  quenching.  The  matter  of  heat  reduction  for 
the  purpose  of  annealing  will  be  considered  in  another 
chapter. 

When  steels  are  heated  to  a  certain  temperature, 
which  will  be  different  in  every  grade  and  analysis 
of  steel,  certain  changes  take  place  in  the  metal. 
These  changes  are  of  physical  and  chemical  nature, 
and  the  point  at  which  the  change  occurs  is  known 
as  the  " critical  temperature"  or  "critical  range"  of 
the  particular  steel  in  question.  The  nature  of  these 
changes  is  known  and  very  ably  discussed  by  many 
authors  of  technical  books  on  the  subject  of  metal- 
lurgy. It  is  not  within  the  scope  of  this  book  to  go 
into  these  technicalities,  and  we  will  therefore  con- 
tent ourselves  with  accepting  the  fact  that  such  a 
point  of  change  actually  does  exist. 

When  steel  is  heated  above  the  critical  tempera- 
ture, the  changes  so  caused  are  such  that,  if  they 
can  be  retained  in  the  steel  after  cooling,  the  physical 
properties  of  the  steel  will  be  entirely  different  from 
those  of  the  same  steel  prior  to  the  change  having 
taken  place.  When  the  temperature  of  a  piece  of 
steel  is  raised  to  a  point  slightly  above  the  critical 
temperature,  the  changes  do  not  occur  instantane- 
ously, a  certain  amount  of  time  being  necessary 
for  this  action.  On  cooling  a  piece  of  steel  from  a 

[43] 


JOSEPH        T.         RYERSON         &         SON 

temperature  above  the  critical  point  (we  will  call 
this  critical  point  No.  1),  providing  that  the  cooling 
is  done  slowly,  the  changes  which  have  occurred 
will  reverse  themselves  and  the  steel  will  return  to 
its  original  condition.  The  temperature  at  which 
the  return  to  original  condition  starts  is  lower  than 
the  No.  1  critical  point  and  this  point  may  be,  for 
convenience,  called  critical  temperature  No.  2. 

In  considering  a  decreasing  temperature  and  the 
change  which  the  steel  undergoes  during  such 
decreases,  the  time  element  is  of  the  utmost  impor- 
tance, inasmuch  as  the  changes  occur  not  instan- 
taneously but  over  a  certain  period  of  time. 

The  whole  operation  of  heat  treating,  therefore, 
depends  upon  the  following  facts: 
First,  that  steel  undergoes  a  change  when  heated 

above  a  certain  point. 

Second,  that  such  change  will  be  reversed  on  suffi- 
ciently slow  cooling,  thus  returning  the  steel  to  its 
original  condition. 

Third,  that  the  changes  can  not  occur  instantane- 
ously. 

Fourth,  that  the  physical  properties  of  the  steel  will 

be  different  provided  the  changes  which  took  place 

on  heating  can  be  retained  in  the  steel  when  in  a 

cold  or  normal  temperature  condition. 

Owing  to  the  fact  that  time  is  required  for  the 

changes  to  occur  on  a  falling  temperature,  we  can, 

by  heating  steel  above  the  critical  point  No.  1  and 

cooling  it  quickly  by  quenching  in  water,  oil,  or 

some  other  medium,  to  a  certain  extent  prevent  the 

return  of  the  steel  to  its  previous  condition. 

It  is  not  possible  to  entirely  prevent  the  return 
of  the  steel  to  its  previous  or  natural  condition. 
From  a  practical  standpoint  the  more  we  do  to 
prevent  the  return  of  the  steel  to  the  natural  con- 
dition the  harder  and  stronger  it  will  be;  therefore, 

[44] 


ALLOY 


STEEL 


I     N 


TOOK 


it  will  be  obvious  that  the  final  physical  properties 
of  the  steel  will  depend  on  the  rate  of  cooling. 

Different  rates  of  cooling  may  be  obtained  by 
using  different  cooling  mediums,  and  also  by  holding 
these  various  cooling  mediums  at  different  tempera- 
tures. The  above  remarks  make  it  clear  that  it  is 
very  necessary  to  maintain  the  quenching  bath  at  a 
uniform  temperature  if  uniform  results  are  to  be 
obtained. 

It  will  now  be  obvious  to  the  reader  why  the 
matter  of  size  of  the  pieces  being  heat  treated  has 
such  an  important  bearing  on  the  final  result.  It  is, 
of  course,  physically  impossible  to  cool  a  6  inch 
round  bar  as  rapidly  as  can  be  done  in  the  case  of 
a  1  inch  round  bar.  The  great  difference  in  the 
final  physical  properties  produced  by  the  different 
rate  of  cooling  is  clearly  shown  in  Table  B. 

TABLE  B 

EFFECT  OF  SIZE  ON  RESULTS  OF  HEAT 
TREATMENT 


SIZE 

TENSILE 
STRENGTH 

Lbs.  per  sq. 
Inch 

ELASTIC 
LIMIT 

Lbs.  per  sq. 
Inch 

EXTENSION 

Per  cent  in 
2  Inch 

CONTRACT- 
ING AREA 
Per  cent  of 
original 
area 

1-in.  Rd. 

138,500 

106,000 

18.80 

60 

2-in.  Rd. 

125,000 

95,000 

19.00 

58 

3-in.  Rd. 

112,000 

84,000 

19.50 

56 

4-in.  Rd. 

107,000 

70,000 

19.00 

54 

5-in.  Rd. 

105,000 

69,000 

18.90 

54 

6-in.  Rd. 

98,000 

68,500 

19.00 

49 

These  tests  were  made  on  steel  of  exactly  the  same  composition 
and  the  heat  treatment  given  was  identical  in  regard  to  quench- 
ing and  drawing  temperatures,  the  difference  being  in  the  time 
required  to  cool  the  pieces  through  a  certain  temperature  range. 
This  illustrates  very  clearly  the  fact  that  the  result  of  heat  treat- 
ment depends  on  the  Rate  of  Cooling,  all  other  factors  such  as  anal- 
ysis, quenching  temperature,  and  final  temperature  being  equal. 


[45] 


JOSEPH        T.        RYERSON        &        SON 

It  is  not  very  practical  to  work  out  a  definite 
chart  indicating  the  probable  effect  of  size  in  heat 
treating,  and  this  matter  must,  therefore,  be  deter- 
mined by  experience  and  by  actual  test. 

Cleanliness  is  of  importance  in  heat  treating  as 
well  as  all  other  manufacturing  operations,  and  is 
particularly  important  in  reference  to  quenching 
baths  and  tanks.  Where  oil  is  used,  it  should  be 
clean,  and  it  must  be  remembered  that  it  will  not 
last  indefinitely.  The  effect  of  the  high  tempera- 
tures on  quenching  oils  will  in  tune  change  their 
specific  heat  or  cooling  ability;  and  this  matter 
must,  therefore,  be  watched  with  care. 

Arrangements  must  be  made  to  keep  the  cooling 
solutions  agitated,  as  otherwise  the  parts  being 
treated  will  raise  the  temperature  of  the  cooling 
medium  in  their  immediate  neighborhood  to  a  high 
degree,  thus  cutting  down  the  cooling  effect. 

Oils  may  be  agitated  by  pump  circulation  which 
carries  the  oil  from  the  tank  out  through  cooling 
colis  and  then  back  to  the  tank,  or  the  piece  may  be 
kept  in  motion  until  it  has  lost  most  of  its  heat. 

When  water  is  used  as  a  cooling  medium,  the 
agitation  problem  is  not  quite  so  hard  to  handle 
inasmuch  as  fresh  water  can  be  constantly  added  to 
the  bath,  and  owing  to  the  low  cost  the  loss  thus 
occasioned  will  not  be  serious. 

The  quenching  tanks  should  be  placed  close  to 
the  furnaces,  inasmuch  as  after  being  removed  from 
the  furnace  the  hot  steel  must  reach  the  quenching 
medium  with  the  least  possible  delay. 

Where  the  pieces  are  light  the  quickest  and  most 
efficient  cooling  can  be  accomplished  by  having  a 
heavy  wire  screen  placed  well  down  in  the  cooling 
medium  on  which  the  pieces  can  rest.  The  screen 
will  allow  the  quenching  medium  to  circulate  freely 
and  the  pieces  will  be  cooled  much  more  rapidly 
than  if  they  were  resting  on  the  bottom  of  the  tank. 

[46] 


ALLOY 


T    E     E     L 


I     N 


TOOK 


With  heavy  parts  such  as  long  bars,  some  mechan- 
ical arrangement  for  suspension  in  the  liquid  quench- 
ing medium  should  be  made,  so  that  either  the  bars 
or  the  bath  can  be  kept  moving  constantly. 

In  quenching  do  not  allow  the  pieces  to  rest  on 
the  bottom  of  the  tank,  because  when  this  is  done 
the  upper  part  of  the  piece  will  be  cooled  much  more 
rapidly  than  the  lower  part  and  uneven  results  and 
possible  warping  will  occur. 


Oil  Quenching  Tank  with  cooling  unit  located  outside  of  building. 

Note  this  system  is  equipped  with  water  spray  pipe  for  use 

when  necessary  to  increase  the  cooling  effect. 


[47] 


JOSEPH        T.        RYERSON        &        SON 


CHAPTER  XI 

DRAWING 

DRAWING  is  a  term  used  to  designate  a  re- 
heating of  steel  that  has  been  heated  and 
quenched.     When   steel   is   quenched   from 
above  the  critical  temperature  No.  1,  it  is  usually 
too  hard  and  does  not  possess  the  necessary  tough- 
ness for  most  purposes.    For  this  reason  the  draw- 
ing or  reheating  process  is  necessary. 

We  have  already  shown  that  by  heating  steel 
above  critical  temperature  No.  1  and  cooling  rapidly 
by  quenching  we  retain  in  the  steel  certain  proper- 
ties induced  by  heating,  owing  to  the  fact  that  we 
have  not  given  the  steel  sufficient  time  during  the 
cooling  process  to  return  to  its  original  condition. 
Considering  a  piece  of  steel  as  it  is  removed  from 
the  quenching  bath,  we  will  now  understand  that 
its  physical  condition  is  fixed  owing  to  the  fact  that 
no  change  can  occur  while  the  steel  remains  below 
a  certain  temperature.  The  tendency  of  the  steel 
is  to  return  to  its  original  condi- 
tion, and  each  increase  of  tem- 
perature above  a  certain  point  will 
allow  the  steel  to  approach  more 
closely  to  its  condition  prior  to  the 
heating  and  quenching  operations. 
The  temperature  at  which  the 
return  to  normal  condition  starts 
will  vary  with  different  steels; 
however,  in  most  cases  this  tem- 
perature will  be  somewhere  between 
Small  Heating  Furnace.  270°  and  300°  Fahr.  The  amount 

[48] 


ALLOY  STEEL  IN  STOCK 

of  change  occurring  will  depend  entirely  on  the  tem- 
perature and  the  time  at  which  the  steel  is  held  at 
this  temperature.  The  change  increases  until  the 
temperature  has  reached  the  critical  point  No.  1, 
when  the  change  will  be  complete  and  the  steel  will 
have  returned  to  exactly  the  same  condition  as  it 
was  prior  to  the  initial  heating  and  quenching.  The 
drawing  should  not  be  carried  beyond  the  critical 
temperature,  as  if  this  is  done  all  the  work  of  quench- 
ing and  drawing  will  be  wasted  and  the  steel  will 
again  be  in  the  same  condition  as  it  was  prior  to  the 
first  quenching.  The  ability  to  partially  return  the 
steel  to  the  normal  condition  is  naturally  very 
valuable,  inasmuch  as  it  will  enable  us  to  produce 
any  desired  degree  of  strength,  toughness,  or  hard- 
ness within  the  range  of  the  particular  steel  which 
we  may  be  using.  The  practical  application  of  this 
operation  is  shown  in  the  tables  in  another  part  of 
this  book. 

Like  all  other  heating  operations,  drawing  must 
be  handled  with  care  and  above  all  with  extreme 
accuracy.  The  hot  oil  bath  gives  the  most  accurate 
method  of  drawing  where  the  temperatures  do  not 
exceed  600°  Fahr.  Molten  lead  may  be  successfully 
used  for  higher  temperatures,  and  in  some  cases, 
where  the  furnace  control  is  good  and  the  proper 
care  is  exercised  in  their  use,  furnaces  will  give 
accurate  and  dependable  drawing. 


[49] 


JOSEPH         T.         RYERSON         &         SON 


CHAPTER  XII 

ANNEALING 


IT  will  sometimes  be  desirable  to  anneal  alloy 
steel  which  may  be  either  in  the  form  of  rolled 
or  hammered  bars  or  forgings.  Such  annealing 
may  be  for  the  purpose  of  rendering  the  steel  softer 
so  that  it  may  be  machined  more  readily,  or  it  may 
be  with  the  idea  of  refinement  of  the  granular  struc- 
ture where  this  has  been  coarsened  by  the  forging 
or  rolling  operation  having  been  finished  at  too  high 
a  temperature.  Internal  stresses  resulting  from  forg- 
ing or  rolling  can  also  be  relieved  by  proper  an- 
nealing, and  sometimes  this  operation  is  very 
desirable. 

The  equipment  necessary  for  annealing  will  be 
similar  to  that  used  for  other  heat  treatment  work, 
and  will  consist  primarily  of  a  furnace  for  raising 
temperatures  together  with  some  means  of  lowering 
temperatures  slowly. 

In  heating  steel  during  the  annealing  process  it  is 
important  that  the  furnace  gases  be  so  proportioned 
that  they  do  not  contain  an  excess  of  oxygen.  Steel 
during  the  annealing  process  is  maintained  at  rel- 
atively high  temperatures  for  a  considerable  length 
of  time,  and  if,  therefore,  the  furnace  atmosphere 
is  of  an  oxidizing  nature,  considerable  decarboniza- 
tion  will  occur  and  a  heavy  scale  will  be  formed  as 
well  as  loss  of  carbon  in  the  surface. 

We  have  already  pointed  out  that  no  change  in 
the  physical  structure  of  the  steel  will  take  place 
unless  the  steel  is  heated  slightly  beyond  the  critical 
temperature  No.  1,  and  therefore,  where  grain  refine- 

[50] 


ALLOY  STEEL  IN  STOCK 

ment  is  desired  the  annealing  temperature  will  be 
above  this  point. 

We  have  already  shown  that  the  slower  the  cooling 
from  above  this  critical  temperature  the  greater  is 
the  opportunity  given  the  structural  changes  to 
reverse  themselves,  thus  bringing  the  steel  back  to 
its  normal  condition.  It  will,  therefore,  be  seen 
that  annealing  consists  of  raising  the  temperature 
of  the  steel  to  a  point  above  the  critical  No.  1  and 
then  allowing  it  to  cool  very  slowly. 

From  the  preceding  explanation  the  reader  under- 
stands that  the  degree  of  annealing  will  depend 
upon  the  selection  of  the  right  heating  temperature 
and  the  rate  of  cooling.  This  annealing  temper- 
ature will,  of  course,  vary  for  different  steels.  On 
page  52  of  this  book  will  be  found  a  table  showing 
the  approximate  figures  to  be  used. 

As  in  all  other  heat  treating,  time  is  a  factor  as 
well  as  temperature,  and  after  the  steel  has  been 
brought  to  the  proper  annealing  heat  it  must  be 
held  at  this  temperature  for  sufficient  length  of 
time  for  the  necessary  changes  to  take  place.  The 
tune  during  which  steel  should  be  held  at  the  an- 
nealing heat  will  depend  primarily  on  the  size  of 
the  pieces.  No  very  definite  rule  can  be  made,  and 
the  actual  time  will  vary  from  a  few  minutes  in  some 
cases  to  several  days  in  others. 

For  small  forgings,  such  as  automobile  engine 
connecting  rods  and  similar  parts,  about  20  to  30 
minutes  at  the  annealing  temperature  will  be  suffi- 
cient to  insure  heat  penetration  and  completion  of 
the  structural  changes.  For  a  bar  6  inches  in  diam- 
eter about  two  or  three  hours  at  the  full  annealing 
heat  should  insure  penetration,  although  these  are 
matters  which  must  be  worked  out  by  experiment 
in  each  particular  case. 

Where  it  is  necessary  that  a  part  be  produced 
having  a  clean,  smooth  surface  after  annealing,  it 

[51] 


JOSEPH         T.         RYERSON         &         SON 

is  usual  to  pack  the  parts  in  some  non-active  ma- 
terial, such  as  pulverized  ashes  or  dry  slaked  lime. 
Other  operators  prefer  to  use  charcoal  or  powdered 
anthracite  coal;  either  of  these  substances  will  give 
satisfactory  results,  the  pieces,  of  course,  being 
packed  in  boxes  having  tight  fitting  lids  or  covers 
which  will  exclude  all  air. 

The  whole  object  of  packing  parts  prior  to  an- 
nealing is  to  exclude  air  and  thus  prevent  oxidization 
and  decarbonization. 

Where  the  steel  is  packed  in  boxes  and  surrounded 
by  one  of  the  previously  mentioned  substances,  it 
must  be  borne  in  mind  that  the  steel  will  not  attain 
the  full  furnace  temperature  owing  to  the  fact  that 
it  is  surrounded  by  poor  conductors  of  heat,  and 
this  matter  must  be  considered  in  regulating  the 
temperature  of  the  furnace. 

One  of  the  best  methods  of  reducing  the  tem- 
perature slowly  is  to  leave  the  pieces  in  the  furnace ; 
shut  off  the  fire  and,  having  closed  the  doors,  close 
up  all  openings  or  cracks  with  clay.  When  closed 
up  tight  the  furnace  will  cool  very  slowly,  and  if  the 
annealing  temperature  has  been  correct  the  anneal- 
ing result  will  in  all  probability  be  entirely  sat- 
isfactory. 

ANNEALING  TEMPERATURES 

STRAIGHT  CARBON  STEELS 

.15  to    .25  Carbon 1570°  Fahr. 

.25  to    .35  Carbon 1550°  Fahr. 

.35  to    .45  Carbon 1525°  Fahr. 

.45  to    .55  Carbon 1500°  Fahr. 

.85  to  1 . 10  Carbon  (Tool  Steel) 1425°  Fahr. 

%}/2  PER  CENT  NICKEL  STEEL 

.  15  to  .25  Carbon .  r^r.^.k  .  .  1530°  Fahr. 

.25  to  .35  Carbon #$W^; . .  1500°  Fahr. 

.35  to  .45  Carbon 1450°  Fahr. 

[52] 


A     L     L     O     Y 


STEEL 


I     N 


S     T     (3     C     K 


CHROME  NICKEL  STEEL 
(S.  A.  E.  Specification  3120  to  3140) 

.  15  to  .25  Carbon 1600°  Fahr. 

.25  to  .35  Carbon 1550°  Fahr. 

.35  to  .45  Carbon 1500°  Fahr. 

Where  alloy  steels  have  been  severely  overheated 
and  a  very  coarse  structure  has  thereby  been  pro- 
duced, the  condition  can  be  frequently  rectified  by 
a  double  annealing  process.  This  process  consists 
of  raising  the  temperature  to  about  180°  Fahr.  over 
the  normal  annealing  temperature,  cooling  quickly 
and  following  this  by  the  regular  annealing,  using 
the  temperatures  given  for  annealing  in  the  above 
table.  The  temperatures  given  for  annealing  are  of 
necessity  only  approximate  and  must  be  considered 
as  such. 


Quenching  Tank  with  coil  for  cold  water  circulation. 


53] 


JOSEPH        T.        RYERSON        &        SON 


CHAPTER  XIII 

TESTING  HEAT  TREATED  STEEL 

ATER  we  have  completed  the  heat  treatment 
of  steel,  provided  the  work  has  been  done 
properly,  we  should  have  a  very  close  idea  of 
just  what  results  we  have  obtained.  In  order  to 
check  our  work,  however,  it  is  desirable  to  submit 
the  heat  treated  parts  to  certain  tests  for  physical 
properties.  Such  tests  will  not  only  tell  us  whether 
or  not  the  steel  is  suitable  for  the  purposes  for 
which  it  is  to  be  used,  but  it  will  also  serve  to  in- 
dicate as  to  whether  or  not  our  equipment,  such  as 
furnaces,  quenching  baths,  pyrometers,  etc.,  have 
been  functioning  properly. 

The  usual  tests  to  which  steels  are  submitted  are 
for  the  purpose  of  determining  the  following  physical 
properties:  Tensile  strength  in  pounds  per  square 
inch,  elastic  limit  in  pounds  per  square  inch,  elonga- 
tion (usually  as  a  percentage  in  2  inches),  and  con- 
traction of  area. 

The  usual  method  of  testing  for  these  physical 
characteristics  is  to  turn  down  a  sample  of  the  steel 
to  a  known  diameter  and  submit  it  to  a  gradually 
increasing  pull  in  one  of  the  standard  testing 
machines.  The  testing  machines  are  so  designed 
that  the  actual  stress  on  the  specimen  can  be  read 
at  all  times,  and  this  stress  is  increased  until  the  spec- 
imen is  fractured,  thus  giving  the  desired  information. 

Testing  machines  are  large,  heavy,  and  expensive, 
and  the  services  of  a  thoroughly  trained  man  are 
necessary  in  order  to  successfully  operate  them. 
Where  considerable  testing  is  to  be  done  a  machine 

[54] 


ALLOY  STEEL  IN  STOCK 

is,  of  course,  a  necessary  investment,  but  otherwise 
it  is  more  economical  to  send  sample  pieces  to  one 
of  the  fully  equipped  commercial  testing  laboratories 
that  handle  this  work  and  furnish  accurate  reports 
of  the  results  obtained. 

It  has  long  been  known  that  a  relation  exists  in 
steel  between  hardness  and  tensile  strength;  and  the 
method  of  determining  the  approximate  tensile 
strength  by  first  determining  the  hardness  may, 
therefore,  be  used. 

Hardness  may  be  ascertained  by  one  of  several 
methods.  The  most  widely  used  methods  are  those 
employing  the  Brinell  testing  machine  and  the  Shore 
scleroscope. 

The  Brinell  system  consists  of  exerting  a  definite 
and  known  pressure  on  a  hard  steel  ball  of  certain 
diameter  which  rests  on  the  surface  of  the  material 
to  be  tested.  The  area  of  the  indentation  made  by 
the  steel  ball  on  the  surface  of  the  specimen  is 
carefully  measured  and  is  used  as  a  basis  for  figuring 
the  so  called  Brinell  hardness  of  the  specimen.  The 
Brinell  machine  is  rather  expensive,  and  where 
accurate  results  are  to  be  obtained  it  must  be  used 
with  great  care.  The  results  are,  however,  entirely 
reliable  within  certain  hardness  ranges.  The 
Brinell  method  does  not  work  very  satisfactorily  on 
extremely  hard  steels,  owing  to  the  fact  that  the 
impression  will  be  too  small  to  be  measured  with 
accuracy,  and  that  the  ball  instead  of  penetrating 
the  sample  will  flatten  out  to  a  certain  extent. 

The  Shore  scleroscope  consists  of  a  glass  tube 
and  a  small  piece  of  extremely  hard  steel  which  is 
free  to  travel  up  and  down  the  center  of  the  tube. 
The  machine  is  so  arranged  that  the  glass  tube  is 
placed  vertically  and  at  right  angles  to  the  surface 
of  the  material  to  be  tested,  and  the  small  piece  of 
steel  is  allowed  to  fall  through  the  tube  from  a 
certain  height.  The  harder  the  sample  to  be  tested 

[55] 


JOSEPH 


T    . 


R    Y    E    R    S    O    N 


SON 


the  higher  will  the  small  piece  of  steel  rebound,  and 
the  amount  of  this  rebound  is  taken  as  a  measure  of 
the  hardness  of  the  sample.  The  scleroscope  is  per- 
haps the  cheapest  of  all  the  standard  hardness  testers, 
and  if  used  with  care  fairly  reliable  results  may  be 
obtained.  The  scleroscope  is  particularly  useful 
in  working  on  hard  material,  and  it  is,  therefore, 
used  for  testing  the  hardness  of  tempered  tool  steel 
dies,  the  teeth  of  hardened  gears,  roller  bearing  and 
ball  bearing  surfaces,  and  other  kindred  work. 

In  the  following  tables  will  be  found  the  Brinell 
and  scleroscope  hardness  numbers  and  the  ap- 
proximate corresponding  tensile  strength  in  pounds 
per  square  inch  on  carbon,  chrome  nickel,  and  3J/2 
per  cent  nickel  steels.  These  tables  are  as  nearly 
accurate  as  possible,  but  must  not  be  taken  as  being 
exact. 

CAKBON  STEEL 


Scleroscope 
Reading 

Brinell 
Reading 

Tensile  Strength  in 
Ibs.  per  sq.  inch 

20 

130 

63,000 

30 

195 

108,000 

40 

260 

150,000 

50 

325 

200,000 

60 

390 

250,000 

70 

455 

290,000 

80 

520 

335,000 

90 

585 

390,000 

MM   10° 

650 

425,000 

CHROME  NICKEL  STEELS 


Scleroscope 
Reading 

Brinell 
Reading 

Tensile  Strength  in 
Ibs.  per  sq.  inch 

20 

141 

74,000 

30 

195 

111,000 

40 

249 

147,000 

50 

303 

183,000 

60 

357 

215,000 

70 

411 

258,000 

80 

465 

292,000 

90 

519 

331,000 

100 

573 

366,000 

[56] 


A     L     L     O     Y 


S     T     E     E     L 


I     N 


STOCK 


3J/2  PER  CENT  NICKEL  STEELS 


Scleroscope 
Reading 

Brinell 
Reading 

Tensile  Strength  in 
Ibs.  per  sq.  inch 

20 

158 

70,000 

30 

213 

100,000 

40 

268 

145,000 

50 

323 

180,000 

60 

378 

225,000 

70 

433 

260,000 

80 

488 

280,000 

90 

543 

320,000 

100 

598 

350,000 

[57] 


JOSEPH         T.         RYERSON         &         SON 


CHAPTER   XIV 

CASE  HARDENING  OR  CARBONIZING 

IT  is  sometimes  desirable  to  produce  a  piece  of 
steel   having   an    intensely   hard    exterior    or 
surface,  intended  to  resist  wear,  coupled  with 
a  tough  and  strong  core  or  center  having  considerable 
resistance  to  shock. 

This  result  is  obtained  by  what  is  commonly 
known  as  case  hardening  or  carbonizing.  This 
process  consists  of  taking  a  comparatively  low 
carbon  steel,  and,  after  having  formed  it  to  the 
desired  shape,  raising  the  carbon  content  on  the 
surface  to  a  sufficiently  high  point  so  that  when 
quenched  it  will  become  extremely  hard.  While 
under  certain  conditions  steel  can  be  made  to  absorb 
carbon,  such  absorption  or  penetration  will  not 
extend  very  far  beneath  the  surface;  and,  therefore, 

when  this  material  is 
quenched  the  interior,  be- 
ing of  low  carbon  content, 
will  merely  be  toughened, 
thus  giving  an  extremely 
hard  surface  with  a  tough 
and  strong  supporting  core 
or  center. 

Various  materials  under 
certain  heat  conditions 
will  give  up  some  of  their  carbon  to  steel,  and  among 
those  commonly  used  may  be  mentioned  charred 
leather,  crushed  and  charred  bone,  charcoal,  and 
certain  gases  which  contain  a  large  percentage  of 
carbon  such  as  carbon  monoxide. 

[58] 


ALLOY  STEEL  IN  STOCK 

In  commercial  case  hardening  the  pieces  to  be 
treated  are  packed  in  an  iron  box  or  container  and 
are  surrounded  with  the  carbonizing  material,  which 
may  consist  of  one  of  the  foregoing  substances  or, 
better,  of  the  numerous  prepared  carbonizing  mix- 
tures that  are  sold  for  this  purpose.  The  box  is  now 
raised  to  a  certain  temperature  in  the  furnace  and 
held  at  this  temperature  for  a  definite  length  of  time. 
When  sufficient  carbon  penetration  has  taken  place 
the  parts  are  subjected  to  various  heat  treatments 
which  will  be  described  later. 

The  rate  of  case  hardening  and  the  depth  of 
penetration  are  controlled  by  the  following  factors: 
First,  the  class  of  steel. 
Second,  the  class  of  carbonizing  mixture. 
Third,  the  shape  of  and  the  material  from  which  trie 

box  or  container  is  made. 
Fourth,  the  temperature  at  which  the  carbonizing  is 

done  and  the  length  of  time  during  which  this 

temperature  is  maintained. 

Roughly  speaking,  the  higher  the  temperature, 
the  more  rapidly  will  the  carbonizing  mixture  give 
up  its  carbon  to  the  steel,  but  this  heat  factor  is 
governed  by  the  degree  of  heat  which  the  steel  can 
stand  without  detrimental  effect;  and,  therefore,  a 
deep  penetration  can  only  be  obtained  safely  by 
using  the  normal  case  hardening  temperature  and 
holding  this  for  a  length  of  time  dependent  on  the 
depth  of  case  required. 

Attention  is  called  to  the  following  points  in 
connection  with  this  work. 

CARBONIZING  MIXTURES 

There  are  many  good  carbonizing  mixtures  avail- 
able, all  having  their  good  points.  However,  the 
following  features  should  be  considered  when 
buying: 

[59] 


JOSEPH         T.         RYERSON         &         SON 

First — Should  have  a  good  heat  conductivity. 

Second — Should  be  uniform  in  granular  size. 

Third — Must  carbonize  at  a  uniform  rate. 

Fourth — Must  be  capable  of  being  used  time  after 
time  in  order  to  be  economical. 

Fifth — Should  not  contain  phosphorus  or  sulphur, 
inasmuch  as  these  may  be  absorbed  by  the  steel. 

Sixth — Must  be  of  uniform  composition  through- 
out so  that  it  will  give  uniform  results  on  all  parts 
of  the  steel  being  carbonized. 

A  very  good  carbonizing  medium  can  be  made  by 
mixing  the  following : 

Barium  Carbonate,  2  Parts. 

Wood  Charcoal,  3  Parts. 

Both  the  barium  carbonate  and  charcoal  must  be 
finely  granulated  and  thoroughly  mixed.  This  mix- 
ture has  an  advantage  in  that  if  spread  out  and 
exposed  to  the  air,  it  will  "  revive,"  owing  to  the 
fact  that  the  barium  oxide  produced  during  the 
carbonizing  process  will  take  up  carbon  dioxide  from 
the  air  and  in  this  way  again  become  barium 
carbonate;  the  charcoal  must  of  course  be  replen- 
ished after  it  has  become  depleted  by  use. 

CASE  HARDENING  BOXES 

The  boxes  used  for  hardening  should  be  sufficiently 
heavy  to  withstand  the  high  temperature  used  for  a 
considerable  length  of  time  without  warping,  and 
should  be  made  of  material  which  is  a  good  heat 
conductor.  It  is  important  that  the  boxes  be  so 
designed  that  after  the  pieces  are  packed  in  them 
they  can  be  closed  so  as  to  exclude  all  air.  Iron  pipe 
is  satisfactory  for  small  pieces,  although  cast  iron 
boxes  are  more  generally  used.  Where  long  runs  are 
contemplated  it  is  sometimes  economical  to  use 
boxes  made  from  certain  cast  alloys.  These  special 
boxes  are  advertised  in  the  trade  journals  and  can 
be  readily  procured. 

[60] 


ALLOY        STEEL       IN        STOCK 

CARBONIZING  FURNACES 

Furnaces  for  carbonizing  should  be  such  that  the 
temperature  can  be  accurately  controlled  over  any 
desired  period  of  time,  and  in  this  respect  they,  of 
course,  do  not  differ  from  furnaces  used  for  other 
heat  treating  operations. 

TEMPERATURE  FOR  CASE  HARDENING 

There  are  so  many  factors,  such  as  the  character 
of  the  steel,  kind  of  case  hardening  mixture  used, 
the  size  of  the  case  hardening  boxes,  depth  of  pene- 
tration desired,  etc.,  that  govern  case  hardening 
temperature  that  it  is  almost  impossible  to  give  any 
accurate  data  on  this  subject.  The  following  list 
will  probably  be  useful  as  a  general  guide  on  this 
subject,  although  it  must  be  modified  to  meet 
special  conditions. 

CARBON  STEEL  S.  A.  E.  1020 
.10  to  .25  carbon,  1625°  to  1725°  Fahr. 

3J^  PER  CENT  NICKEL  STEEL  S.  A.  E.  2320 
.15  to  .25  carbon,  1600°  to  1650°  Fahr. 

CHROME  NICKEL  STEEL  S.  A.  E.  3120 
.15  to  .25  carbon,  1625°  to  1700°  Fahr. 

DEPTH  OP  PENETRATION 

The  depth  of  penetration  depends  on  numerous 
factors  which  have  already  been  mentioned,  and, 
owing  to  there  being  so  many  things  that  have  a 
bearing  on  this  matter,  it  is  hardly  practical  to 
make  any  definite  statement  in  regard  to  depth  of 
penetration  which  may  be  expected  for  a  given  time 
and  temperature.  As  a  general  guide  to  what  may 
be  expected,  when  working  with  a  straight  carbon 

[61] 


JOSEPH         T..RYERSON 


SON 


steel  using  the  previously  mentioned  barium  car- 
bonate mixture,  the  accompanying  table  can  be 
referred  to,  although  this  is  only  approximate. 


APPROXIMATE  CARBON 

APPROXIMATE  CARBON 

PENETRATION  AT  1650°F. 

PENETRATION  AT  1775°F. 

Hours 

Depth  in  Inches 

Hours 

Depth  in  Inches 

1 

0.030 

1 

0.040 

2 

0.045 

2 

0.050 

3 

0.050 

3 

0.075 

4 

0.060 

4 

0.085 

5 

0.065 

5 

0.098 

6 

0.070 

6 

0.110 

7 

0.080 

In  case  hardening  it  must  be  remembered  that 
the  temperature  of  the  furnace  is  not  the  same  as 
the  temperature  of  the  piece  being  case  hardened. 
The  heat  has  to  first  penetrate  through  the  walls  of 
the  box  and  then  through  the  case  hardening  mix- 
ture, and  consequently  the  piece  being  carbonized 
will  be  at  a  lower  temperature  than  the  furnace 
itself. 

Where  accurate  results  are  required  it  is  a  good 
plan  to  make  a  few  experiments  by  placing  a  thermo 
couple  in  contact  with  or  near  the  pieces  being 
treated,  and  also  another  thermo  couple  in  the 
furnace  so  the  difference  in  temperature  between  the 
furnace  and  the  piece  can  be  observed. 

HEAT  TREATMENT  AFTER  CARBONIZING 
When  carbonization  has  been  completed  the 
hardening  process  is  next  undertaken,  and  it  is  of 
the  greatest  importance  that  this  be  carried  out 
accurately  and  scientifically  if  uniform  and  depend- 
able results  are  to  be  obtained. 

It  must  be  remembered  that  the  carbonized  pieces 
have  been  held  at  a  temperature  considerably  above 
the  critical  range  during  a  long  period  of  time;  and 
it,  therefore,  follows  that  the  grain  of  the  steel  has 
been  coarsened. 


[62] 


ALLOY  STEEL.    IN  STOCK 

After  hardening,  the  surface  or  case  of  a  carbon- 
ized part  will  be  intensely  hard  and  brittle,  and  will 
in  consequence  not  have  any  great  degree  of  tough- 
ness. For  these  reasons  it  is  necessary  that  we 
depend  on  the  center  or  core  of  the  piece  to  support 
the  hard  outside  surface;  and  we  must,  therefore, 
bend  our  efforts  toward  putting  the  core  in  the 
best  possible  condition  in 
regard  to  granular  struc- 
ture, strength,  and  elas- 
ticity. 

Speaking  generally , the 
best  method  of  obtaining 
this  result  is  by  first  cool- 

,,  i        ,        ,,  .  Sheet  Mill. 

ing  the  parts  slowly,  this 

being  accomplished  by  allowing   them  to  remain 

in    the  case  hardening  boxes  until  comparatively 

cold,  then  removing  and  proceeding  with  a  refining 

treatment. 

On  page  92  will  be  found  formulae  which  may  be 
used  as  a  general  guide  for  carbonizing  operations. 
The  important  fact  to  remember  is  that  no  set  rule 
can  be  given  to  cover  all  cases.  Where  a  new  job 
is  undertaken  time  and  money  will  be  saved  if  the 
heat  treater  will  take  samples  of  the  steel  he  intends 
working  with,  and  submit  them  to  the  process  he 
contemplates  using  for  the  work  in  hand.  Should 
the  treatment  contemplated  not  be  correct,  the 
samples  will  show  it  and  steps  can  be  taken  to  avoid 
the  loss  of  material  and  time  that  would  result  had 
tests  not  been  made.  It  must  be  realized  that 
experience  and  patience  are  necessary  when  good 
dependable  results  are  to  be  obtained.  Your  first 
batch  may  turn  out  well.  If  it  does  you  are  very 
fortunate,  but  if  it  does  not,  don't  be  discouraged. 
If  you  fail  there  is  a  reason.  Study  it  out  and  correct 
it  next  time. 

[63] 


JOSEPH      T.      RYERSON      &      SON 

PACKING 

Inasmuch  as  the  heat  in  case  hardening  must 
penetrate  first  through  the  containing  boxes  and 
then  through  the  case  hardening  mixture  before 
reaching  the  surface  of  the  steel,  it  is  obvious  that  a 
uniform  temperature  on  all  parts  of  the  piece  being 
case  hardened  can  not  be  obtained  unless  the  piece 
is  surrounded  on  all  sides  by  equal  thickness  of  case 
hardening  mixture.  As  the  rate  and  depth  of 
penetration  depend  upon  the  temperature,  it  is 
obvious  that  to  obtain  uniform  results  we  must 
surround  the  pieces  being  case  hardened  as  nearly 
as  possible  with  a  uniform  amount  of  case  hardening 
mixture. 

Packing  is  an  important  operation  in  case  harden- 
ing and  care  should  be  used  to  see  that  the  pieces 
being  treated  are  placed  as  nearly  as  possible  in  the 
center  of  the  case  hardening  box. 

It  is  not  wise  to  use  very  large  case  hardening 
boxes  or  to  endeavor  to  place  too  many  parts  in  the 
one  box.  When  this  is  done  the  parts  nearest  the 
wall  of  the  box  will  naturally  attain  a  very  much 
higher  temperature  than  those  near  the  center,  and 
a  nonuniform  result  will  be  secured. 

Superficial  Case  Hardening.  Where  an  extremely 
thin  surface  of  hardened  steel  is  required,  and  in 
cases  where  such  hardening  must  be  obtained 
quickly,  the  following  method  may  be  employed, 
although  the  results  are  not  uniform  nor,  as  a  rule, 
particularly  good: 

Melt  sufficient  potassium  cyanide  in  a  pot  so  as 
to  form  a  bath  in  which  the  parts  to  be  case  hardened 
may  be  immersed. 

Raise  the.  temperature  of  the  molten  potassium 
cyanide  to  about  1550°  Fahr.,  and  allow  the  parts 
to  remain  in  this  bath  for  about  fifteen  minutes. 
The  length  of  time  that  the  parts  remain  in  the 

[64] 


ALLOY  STEEL          IN          STOCK 

cyanide  bath  will  depend  on  their  size,  but  in  any 
event  it  will  be  necessary  that  they  remain  for  a 
sufficient  length  of  time  to  insure  uniform  heat 
penetration  all  the  way  through  to  the  center. 

Ten  minutes  immersion  will  give  a  penetration  of 
about  0.005  inch  and  twenty  minutes  a  penetration 
of  about  0.01  inch  when  using  a  straight  carbon 
steel  such  as  S.  A.  E.  1020. 

The  pieces  should  be  removed  from  the  cyanide 
bath  and  plunged  directly  into  cold  water,  after 
which  the  surface  will  be  found  to  be  hard  and  the 
interior  core  in  a  fairly  good  condition. 

Great  care  must  be  used  in  employing  a  molten 
cyanide  bath,  inasmuch  as  this  material  will  give 
off  highly  poisonous  fumes  which  should  be  carried 
off  by  suitable  apparatus. 

In  case  hardening  it  must  be  borne  in  mind  that 
there  are  two  objectives:  The  first,  which  is  well 
known  and  commonly  recognized,  consists  in 
obtaining  a  hard  exterior  surface,  intended,  of 
course,  to  resist  wear  and  abrasion.  The  other, 
which  is  frequently  overlooked  although  of  equal 
importance,  is  the  building  up  of  a  core  of  adequate 
strength  and  toughness  so  that  it  may  give  the 
proper  support  to  the  exterior  or  wearing  surface. 

In  case  hardening  we  believe  it  very  necessary  to 
examine  the  finished  pieces  in  a  more  comprehensive 
manner  than  merely  testing  the  exterior  for  hard- 
ness. The  core  examination  referred  to  can  be 
carried  out  by  either  cutting  through  one  of  the 
pieces,  polishing  the  section  and  subjecting  it  to 
microscopic  examination,  or,  in  the  event  of  the  lack 
of  the  necessary  equipment  for  such  examination,  a 
very  good  idea  can  be  obtained  by  partially  cutting 
through  the  piece  and  then  fracturing.  This  will 
give  an  opportunity  to  examine  the  granular  struc- 
ture of  the  steel,  and  the  thickness  of  the  case. 


[65] 


JOSEPH        T.        RYERSON        &        SON 


CHAPTER  XV 

GENERAL  REMARKS 

HAVING  read  the  previous  chapters  the  reader 
will  now  understand  the  reasons  underlying 
the  following  general  remarks  on  the  subject 
of  the  use  of  alloy  steels. 

If  you  are  sure  of  what  particular  steel  to  use  for 
a  certain  purpose,  well  and  good;  but  if  doubt  exists 
in  your  mind,  put  the  matter  up  to  some  reliable 
seller  of  this  material.  The  sales  department  of  the 
mills  and  the  large  warehouses  are  handling  thou- 
sands of  tons  of  alloy  steel  every  day,  and  their  wide 
experience  will  undoubtedly  have  covered  the  point 
on  which  you  are  not  sure. 

Do  not  buy  too  much  on  a  price  basis.  Original 
cost  must  naturally  be  taken  into  account;  but  in 
view  of  the  large  amount  of  work  that  is  done  on 
alloy  steel  in  the  way  of  machining  and  heat  treating 
and  the  vital  importance  of  the  parts  manufactured 
being  up  to  standard,  it  is  absolutely  essential  that 
first  class  material  be  obtained.  Remember  that 
analysis  is  not  the  only  point  to  be  considered  in  the 
selection  of  alloy  steels.  Freedom  from  pipes, 
seams  and  other  defects,  accuracy  in  the  matter  of 
size,  straightness  of  the  bars,  finish  of  the  surface, 
and  many  other  points  are  of  great  importance. 
Steel  may  conform  to  your  specification  in  analysis 
and  yet  be  made  in  such  a  way  that  it  will  develop 
cracks,  checks,  or  other  defects  when  it  is  subjected 
to  the  violent  action  of  a  quenching  process. 

In  heating  alloy  steels,  do  not  place  a  cold  bar 
in  an  extremely  hot  furnace.  This  will  apply  more 
in  the  case  of  larger  bars,  and  the  reason  will  be 

[66] 


ALLOY          STEEL          IN          STOCK 

obvious  if  the  notes  on  this  subject  as  given  in 
another  part  of  this  book  are  read.  Do  not  expect 
to  get  the  same  physical  properties  from  a  10  inch 
round  forging  as  you  will  from  a  1  inch  round  bar 
just  because  the  analysis  may  be  the  same  and 
because  you  give  it  the  same  heat  treatment.  Where 
high  physical  properties  are  required  from  large 
forgings  or  large  rolled  bars,  the  desired  result  can 
to  a  certain  extent  be  obtained  by  using  a  quenching 
temperature  higher  than  that  which  would  be  used 
with  a  smaller  section.  However,  irrespective  of  the 
size  of  the  bar,  the  quenching  temperature  must  not 
be  raised  to  a  point  which  will  be  detrimental  to  the 
steel.  As  a  safe  rule,  do  not  exceed  the  quenching 
temperatures  given  in  this  book  by  more  than  150° 
Fahr.  Where  large  sections  are  being  heat  treated, 
higher  physical  properties  will  be  obtained  by 
raising  the  temperature,  as  already  mentioned,  and 
by  using  a  quicker  quenching  medium;  thus  cold 
water  may  be  substituted  for  oil  in  certain  cases. 

Do  not  place  a  heavy  flat  bar  directly  on  the  brick 
bottom  of  a  furnace  and  then  expect  the  lower  part 
of  the  bar  to  have  the  same  temperature  as  the  top. 
Keep  the  pieces  which  you  are  heating  slightly 
raised  from  the  bottom  of  the  furnace  so  that  the 
hot  gases  can  circulate  around  them,  but  in  doing 
so  place  your  supports  sufficiently  close  together  so 
that  the  hot  bars  will  not  sag  down  between  the 
supports  and  thus  become  bent  and  crooked.  A  bar 
can  be  heated  uniformly  by  placing  it  on  the  bottom 
of  the  furnace  provided  that  it  is  turned  over  at  fre- 
quent intervals.  This  method  is  satisfactory  only 
in  cases  where  a  few  pieces  are  being  heated  at  once 
and  where  the  operator  can  give  the  time  necessary 
to  constantly  watch  the  heating  operation.  So 
arrange  your  shop  that  the  distance  between  your 
furnace  and  the  quenching  bath  is  as  short  as 
possible.  As  soon  as  a  steel  has  reached  its  proper 

[67] 


JOSEPH        T.        RYERSON        &        SON 

quenching  temperature  all  the  way  through  to  the 
center,  it  should  be  immediately  quenched,  and  it 
should  be  quenched  on  a  rising  or  stationary  heat 
and  not  on  a  falling  heat.  If  the  distance  between 
the  furnace  and  the  quenching  bath  is  great,  or  if 
the  method  of  handling  the  steel  is  clumsy  and 
inefficient,  considerable  time  will  elapse  between 
removing  the  bars  from  the  furnace  and  the  actual 
quenching.  When  this  condition  exists  it  will  be 
necessary  to  overheat  the  bars  in  the  first  instance, 
which  will  tend  to  give  a  poor  result. 

If  time  is  lost  between  the  removal  of  steel  from 
the  furnace  and  the  quench,  and  should  the  bars  be 
heated  to  the  correct  quenching  temperature,  then 
by  the  tune  they  reach  the  bath  they  will  have 
dropped  below  this  point,  and,  in  consequence,  the 
heat  treatment  will  not  be  effective. 

When  you  have  finished  your  work  and  submitted 
it  to  physical  tests,  you  may  find  that  your  physical 
properties  are  either  higher  or  lower  than  you 
intended  them  to  be.  The  remedy  will,  of  course, 
lie  in  a  change  of  the  heat  treatment  formula  that 
you  originally  used;  and  it  is,  therefore,  obvious  that 
accurate  records  of  all  operations  should  be  kept. 

It  is  a  good  plan,  where  considerable  work  is 
being  done,  to  use  a  regular  heat  treatment  form. 
A  place  for  the  customer's  name,  order  numbers, 
description  of  the  parts,  sizes,  weights,  etc.,  should 
appear  at  the  top.  Under  this  should  appear  your 
shop  instructions  or  heat  treatment  formula,  and 
opposite  this  space  there  should  be  blank  spaces  for 
the  shop  men  to  fill  in  the  actual  temperatures  and 
tunes  which  were  used  in  executing  the  order. 

Such  a  record  properly  kept  will  give  invaluable 
information  in  reference  to  any  particular  order  that 
has  been  handled  in  the  past,  and  can  also  be  used 
as  a  basis  for  determining  rapidly  and  accurately  the 
most  desirable  heat  treatment  formula  for  other  work. 

[68] 


ALLOY 


STEEL 


I     N 


STOCK 


Universal  Mill.    Rolls  plates  and  bars  on  all  four  sides. 

Insist  on  the  heat  treating  shop  being  kept  clean 
and  neat,  and  do  not  allow  refuse  bars  and  other 
scrap  to  accumulate.  Such  material  gets  in  the  way 
and  cuts  down  the  general  shop  efficiency,  and  there 
is  always  a  possibility  of  bars  of  different  analysis 
getting  mixed  up. 

In  selecting  shop  equipment  for  heat  treating,  do 
not  depend  on  your  own  judgment  too  much  unless 
you  have  had  considerable  past  experience.  Turn 
your  problems  over  to  reliable  furnace  people,  and 
thus  get  the  benefit  of  their  experience  for  which 
they  have  probably  paid  a  good  price. 

As  we  have  explained  elsewhere,  rapid  heating 
tends  to  expand  the  outside  of  a  bar  more  quickly 
than  the  inside,  thus  giving  it  a  tendency  to  crack. 
The  reverse,  of  course,  is  true  in  quenching,  inasmuch 

[69] 


JOSEPH        T.        RYERSON        &        SON 

as  the  outside  of  the  bar  will  shrink  more  rapidly 
than  the  inside,  and  this  also  has  a  tendency  to 
crack  the  steel.  For  these  reasons,  it  is  obvious  that 
square  corners  are  to  be  avoided  as  much  as  possible, 
and  wherever  a  radius  or  fillet  can  be  used  it  renders 
the  heat  treatment  much  more  safe. 

Don't  try  to  heat  a  piece  of  steel  to  700°  Fahr.  in 
a  furnace  that  shows  a  temperature  of  1100  or  1200° 
Fahr.  In  other  words,  have  your  furnace  at  the 
maximum  temperature  which  you  desire  the  steel 
to  attain,  and  then  let  the  steel  come  up  to  the  full 
furnace  temperature.  Where  a  furnace  temperature 
is  used  which  is  in  excess  of  the  temperature  desired 
in  the  steel,  the  outside  part  of  the  piece  will  reach 
the  desired  temperature  before  the  inside,  and  you 
will  not  be  able  to  allow  the  steel  to  remain  in  the 
furnace  for  sufficient  length  of  time  for  the  heat  to 
penetrate  all  the  way  through. 

Remember  in  drawing  that  the  time  element  is  of 
importance,  and  it  is  better  to  use  a  slightly  lower 
temperature  for  a  longer  period  of  time,  inasmuch 
as  the  changes  brought  about  in  the  structure  of  the 
steel  by  a  certain  drawing  temperature  are  more 
uniform  throughout  the  whole  piece  when  this 
temperature  can  be  held  for  a  considerable  length  of 
tune.  Bear  in  mind  that  a  certain  drawing  tem- 
perature held  for  an  hour  will  produce  the  same 
physical  properties  as  a  much  higher  temperature 
held  for  ten  minutes.  The  result  of  the  long  draw 
will,  however,  be  more  uniform  and  better. 

When  case  hardening,  select  a  good  grade  of  case 
hardening  mixture  made  by  reliable  people;  by  so 
doing  your  work  will  be  more  rapidly  handled, 
carbon  penetration  will  be  more  uniform,  and  the 
operation  will  be  more  economical  inasmuch  as  you 
will  be  able  to  use  the  mixture  over  and  over  again 
with  less  frequent  renewal  than  is  necessary  with  a 
cheap  compound. 

[70] 


ALLOY  STEEL  IN  STOCK 

When  carbonizing  any  piece  use  a  pot  of  suitable 
size.  At  no  point  should  there  be  less  than  1J4  inches 
of  case  hardening  mixture  between  the  inside  of  the 
pot  and  any  surface  of  the  piece  being  carbonized, 
and  the  more  nearly  1J^  inches  of  case  hardening 
mixture  can  be  maintained  all  the  way  round  the 
more  uniform  will  be  the  result. 

Always  allow  your  carbonized  parts  to  cool  down 
slowly  after  the  carbonizing  process.  If  possible, 
allow  the  pots  and  their  contents  to  cool  down  out- 
side of  the  furnace  and  then  follow  the  heat  treating 
instructions  which  are  given  elsewhere. 

Where  pieces  are  to  be  case  hardened,  do  not  be 
satisfied  with  your  work  just  because  you  have 
obtained  a  hard  surface.  A  piece  of  common  cold 
rolled  shafting  or  screw  stock  or  an  ordinary  mild 
steel  bar  can,  by  case  hardening,  be  made  just  as 
hard  on  the  surface  as  the  highest  grade  of  chrome 
nickel  or  other  alloy  steel.  This  is  no  indication, 
however,  that  a  part  has  been  produced  which  will 
do  the  work  of  a  properly  case  hardened  alloy  steel 
part.  In  some  certain  instances  surface  hardness  is 
the  only  characteristic  desired  in  case  hardened  work, 
but  as  a  general  thing  the  case  hardened  part  must 
have  strength  as  well  as  hardness,  and  this  can  only 
be  obtained  to  the  maximum  degree  by  the  use  of  a 
high  grade  alloy  steel,  properly  treated. 

This  book  has  made  no  attempt  to  cover  the 
technical  features  of  alloy  steel  problems,  and  it 
has  been  necessary  to  write  in  a  very  general  way, 
only  covering  a  few  of  the  more  important  points. 
The  use  of  alloy  steel  will  develop  many  difficult 
problems,  a  solution  of  which  can  only  be  given  by 
experience.  Should  you,  therefore,  be  uncertain  in 
regard  to  selection  of  an  alloy  steel,  its  heat  treat- 
ment, or  its  application,  do  not  guess  at  the  answer 
to  your  question,  but  put  it  up  to  the  people  from 
whom  you  are  purchasing  your  steel. 

[71] 


JOSEPH        T.        RYERSON        A        SON 

Watch  your  furnace  atmosphere.  An  excess  of 
air  is  bound  to  give  you  trouble.  The  surface  of 
your  steel  will  decarbonize  and  will,  therefore,  not 
harden  as  it  should,  and  heavy  scale  will  be  formed, 
sometimes  ruining  parts  that  are  to  be  machined, 
or  at  any  rate  giving  the  machine  shop  a  great  deal 
of  trouble  with  cutting  tools  that  are  called  upon  to 
remove  this  hard  scale. 

In  forging  alloy  steels  remember  that  steels  con- 
taining chromium  must  not  be  forged  at  low  heats, 
inasmuch  as  this  will  develop  defects  in  the  material. 
The  low  limit  of  heat  for  forging  steel  containing 
chromium  will,  of  course,  depend  upon  the  percent- 
age of  carbon  and  chromium  present,  but  it  is  fairly 
safe  to  assume  that  chrome  nickel  steels  should  not 
be  forged  at  a  temperature  of  less  than  1550°  Fahr. 

Chrome  nickel  steel  of  a  high  carbon  content  (from 
.55  to  .65  carbon),  when  properly  heat  treated  makes 
a  very  fine  die  block  and  one  which,  while  sufficiently 
soft  to  be  machined,  is  hard  enough  and  tough 
enough  to  last  for  a  long  period  of  time.  This  is  a 
great  advantage  in  making  certain  drop  forge  dies, 
owing  to  the  fact  that  the  danger  in  quenching  a 
machined  die  is  eliminated.  The  manufacture  of 
alloy  steel  die  blocks  is  a  specialty  which  can  not  be 
covered  in  this  book,  although  those  interested  can 
obtain  full  information  from  the  alloy  steel  producers. 

When  difficulty  is  experienced  in  getting  furnace 
temperature  so  adjusted  that  scaling  will  not  occur, 
the  difficulty  may  be  overcome  by  placing  in  the 
furnace  some  charcoal  or  a  piece  of  wood.  The  wood 
or  charcoal  will  combine  readily  with  any  free 
oxygen  that  may  be  present  and  thus  prevent 
scaling  or  decarbonization  of  the  steel. 


[72] 


ALLOY       STEEL       IN       STOCK 
CHECKING  PYROMETERS: 

This  operation  is  most  important  and  can  be  taken 
care  of  without  the  use  of  expensive  equipment. 
Take  a  clean  crucible  pot  (fire  clay  or  iron)  and  melt 
in  it  some  pure  common  table  salt  (sodium  chloride) . 
Increase  the  temperature  to  about  1625°  Fahr.  and 
then  put  the  thermo  couple  (without  protecting 
tube)  in  the  bath.  As  soon  as  the  indicator  shows 
that  the  theremo  couple  has  reached  the  temperature 
of  the  salt,  remove  the  pot  from  the  fire  and  allow  it 
to  cool.  During  the  cooling  operation  readings  of 
the  indicator  should  be  taken  every  ten  seconds  and 
the  result  plotted  as  a  time  temperature  curve.  The 
kick  or  flat  spot  in  the  curve  will  show  the  point  at 
which  the  salt  solidifies  or  freezes.  This  point 
should  be  1474°  Fahr.,  and  if  your  pyrometer 
indicates  a  different  point  you  will  know  just  what 
correction  to  make  in  your  reading. 


Quenching  Tank,  with  Circulating  Pump. 


[73] 


JOSEPH        T.        RYERSON        &        SON 


S.  A.  E.  SPECIFICATIONS 

A  system  of  numbers  has  been  adopted  for  the 
naming  of  practically  all  the  standard  grades  of  alloy 
steels.  These  numbers  give  a  very  convenient  way  of 
indicating  a  certain  alloy  steel  and  can  be  used  in 
sending  telegrams,  letters,  or  shop  drawings  and 
many  other  places  where  a  full  description  of  the 
steel  would  take  up  a  lot  of  room. 

The  first  figure  indicates  the  class  of  steel.  The 
second  figure  indicates  the  approximate  percentage 
of  the  principal  alloying  element.  The  last  two  or 
three  figures  represent  the  carbon  desired  in  one 
hundredths  of  one  per  cent  or  "points." 

The  key  list  of  first  figures  is  as  follows: 

1 — Carbon  Steels. 

2— Nickel  Steels. 

3 — Chrome  Nickel  Steels 

5 — Chromium  Steels. 

6 — Chrome  Vanadium  Steels. 

9 — Silico-Manganese  Steels. 

From  the  above  SAE  3120  is  a  chrome  nickel  steel 
of  about  1  per  cent  (1  to  1^)  nickel,  carbon  0.20 
(15  to  25). 

SAE  2335  is  a  nickel  steel  of  about  3  per  cent 
(3.25-3.75)  nickel,  carbon  0.35  (30-40). 

SAE  6150  is  a  chrome  vanadium  steel  of  about 
1  per  cent  chrome  (0.80  to  1.10),  carbon  0.50  (45-55). 

SAE  51120  is  a  chromium  steel  of  about  1  per 
cent  chrome  (90-1.10),  carbon  1.20  per  cent  (1.10- 
1.30). 

[74] 


ALLOY 


STEEL 


I     N 


S    T    O    C 


NICKEL  STEEL  35-45  CARBON 

SAE  SPECIFICATION  2340 
Quench  in  oil  at  1425°  to  1475°  Fahr. 


Drawing 
Tempera- 
ture 

Tensile 
Strength 

Elastic 
Limit 

Red.  of 
Area 

Ext.  in 
2  Inch 

Brinell 
Hardness 

Sclero- 
scope 
Hardness 

400 

240,000 

215,000 

32.5% 

10.0% 

450 

70 

500 

230,000 

204,000 

34.5% 

11.0% 

427 

65 

600 

215,000 

190,000 

37.5% 

12.0% 

400 

61 

700 

196,000 

171,000 

42.0% 

13.0% 

370 

56 

800 

175,000 

150,000 

47.0.% 

14.0% 

335 

51 

900 

155,000 

130,000 

51.0% 

16.0% 

295 

46 

,000 

135,000 

110,000 

55.0% 

18.0% 

260 

42 

,100 

117,000 

92,000 

58.0% 

20.0% 

235 

38 

,200 

105,000 

78,000 

60.0% 

21.5% 

215 

36 

,300 

96,000 

69,000 

61.0% 

22.0% 

205 

35 

,400 

90,000 

60,000 

62.5% 

22.5% 

200 

35 

NICKEL  STEEL  25-35  CARBON 

SAE  SPECIFICATION  2330 
Quench  in  Oil  at  1450°  to  1500°  Fahr. 


Drawing 
Tempera- 
ture 

Tensile 
Strength 

Elastic 
Limit 

Red.  of 
Area 

Ext.  in 
2  Inch 

Brinell 
Hardness 

Sclero- 
scope 
Hardness 

400 

220,000 

190,000 

35% 

10% 

436 

61 

500 

210,000 

182,000 

11% 

420 

59 

600 

198,000 

170,000 

40% 

12% 

400 

57 

700 

180,000 

154,000 

44% 

13% 

370 

54 

800 

160,000 

135,000 

49% 

14% 

330 

50 

900 

140,000 

115,000 

54% 

16% 

290 

45 

1,000 

120,000 

95,000 

59% 

18% 

250 

41 

1,100 

104,000 

77,000 

63% 

20% 

210 

37 

1,200 

92,000 

64,000 

66% 

22% 

180 

34 

1,300 

85,000 

55,000 

68% 

24% 

162 

32 

1,400 

80,000 

48,000 

70% 

25% 

150 

30 

[75] 


JOSEPH 


RYERSON        &        SON 


NICKEL  STEEL  15-25  CARBON 

SAE  SPECIFICATION  2320 
Quench  in  oil  at  1475°  to  1525°  Fahr. 


Drawing 
Tempera- 
ture 

Tensile 
Strength 

Elastic 
Limit 

Red.  of 
Area 

Ext.  in 
2  Inch 

Brinell 
Hardness 

Sclero- 
scope 
Hardness 

400 

170,000 

140,000 

45% 

11.0% 

375 

55 

500 

168,000 

136,000 

46% 

12.0% 

368 

54 

600 

162,000 

130,000 

48% 

13.5% 

355 

52 

700 

155,000 

123,000 

51% 

15.5% 

340 

50 

800 

145,000 

112,000 

55% 

18.5% 

310 

46 

900 

130,000 

99,000 

60% 

21.5% 

280 

42 

1,000 

112,000 

84,000 

65% 

25.0% 

240 

38 

1,100 
1,200 
1,300 

96,000 
82,000 
75,000 

68,000 
54,000 
45,000 

69% 
72% 

74% 

27.0% 
29.0% 
30.0% 

200 
165 
140 

34 
31 

29 

1,400 

70,000 

38,000 

75% 

31.0% 

125 

27 

210  Brinell  considered  good  for  machining  properties. 


CHROME  NICKEL  STEEL  35-45  CARBON 

SAE  SPECIFICATION  3140 
Quench  in  oil  at  1475°  to  1500°  Fahr. 


Drawing 
Tempera- 
ture 

Tensile 
Strength 

Elastic 
Limit 

Red.  of 
Area 

Ext.  in 
2  Inch 

Brinell 
Hardness 

Sclero- 
scope 
Hardness 

400 

220,000 

190,000 

27% 

7.5% 

425 

65 

500 

210,000 

185,000 

28% 

8.0% 

410 

64 

600 

205,000 

175,000 

30% 

9.0% 

390 

62 

700 

195,000 

160,000 

34% 

10.5% 

370 

59 

800 

175,000 

140,000 

39% 

12.5% 

345 

56 

900 

150,000 

126,000 

46% 

14.0% 

315 

52 

1,000 

130,000 

105,000 

52% 

16.0% 

285 

47 

1,100 

115,000 

94,0,00 

56% 

17.0% 

255 

42 

1,200 

100,000 

84,000 

60% 

18.0% 

225 

38 

1,300 

93,000 

80,000 

61% 

19.0% 

215 

36 

1,400 

90,000 

75,000 

62% 

20% 

210 

35 

[76] 


ALLOY 


STEEL 


I    N 


TOOK 


CHROME  NICKEL  STEEL  30-40  CARBON 

SAE  SPECIFICATION  3135 
Quench  in  oil  at  1475°  to  1500°  Fahr. 


Drawing 
Tempera- 
ture 

Tensile 
Strength 

Elastic 
Limit 

Red.  of 
Area 

Ext.  in 
2  Inch 

Brinell 
Hardness 

Sclero- 
scope 
Hardness 

400 

210,000 

170,000 

33% 

10.0% 

425 

58 

500 

205,000 

165,000 

36% 

10.0% 

400 

56 

600 

200,000 

160,000 

40% 

10.5% 

375 

54 

700 

190,000 

145,000 

45% 

11.0% 

360 

52 

800 

170,000 

130,000 

49% 

12.0% 

340 

49 

900 

150,000 

115,000 

54% 

13.5% 

310 

45 

1,000 

130,000 

100,000 

58% 

14.5% 

280 

41 

1,100 

115,000 

90,000 

61% 

16.0% 

250 

38 

1,200 

100,000 

80,000 

64% 

17.5% 

225 

35 

1,300 

90,000 

75,000 

66% 

19.0% 

215 

33 

1,400 

85,000 

72,000 

67% 

21.0% 

210 

30 

CHROME  NICKEL  STEEL  25-35  CARBON 

SAE  SPECIFICATION  3130 
Quench  in  oil  at  1500°  to  1525°  Fahr. 


Drawing 
Tempera- 
ture 

Tensile 
Strength 

Elastic 
Limit 

Red.  of 
Area 

Ext.  in 
2  Inch 

Brinell 
Hardness 

Sclero- 
scope 
Hardness 

400 

190,000 

155,000 

37.5% 

10% 

365 

50 

500 

188,000 

150,000 

41.0% 

11% 

360 

49 

600 

180,000 

140,000 

46.0% 

12% 

350 

48 

700 

167,000 

128,000 

52.0% 

13% 

325 

46 

800 

150,000 

115,000 

59.0% 

15% 

315 

43 

900 

134,000 

102,000 

63.0% 

17% 

282 

40 

1,000 

120,000 

90,000 

65.0% 

20% 

260 

38 

1,100 

104,000 

81,000 

66.0% 

23% 

223 

35 

1,200 

92,000 

76,000 

68.0% 

26% 

215 

32 

1,300 

86,000 

72,000 

69.0% 

28% 

210 

31 

1,400 

80,000 

70,000 

70.0% 

30% 

200 

30 

[77] 


JOSEPH        T.        RYEE80N 


SON 


CHROME  NICKEL  STEEL  15-25  CARBON 

SAE  SPECIFICATION  3120 
Quench  in  oil  at  1575°  to  1600°  Fahr. 


Drawing 
Tempera- 
ture 

Tensile 
Strength 

Elastic 
Limit 

Red.  of 
Area 

Ext.  in 
2  Inch 

Brinell 
Hardness 

Sclero- 
scope 
Hardness 

400 

160,000 

120,000 

52.5% 

15.0% 

275 

46 

500 

155,000 

116,000 

54.0% 

15.5% 

265 

45 

600 

148,000 

110,000 

57.0% 

16.0% 

250 

44 

700 

137,000 

102,000 

61.0% 

16.5% 

240 

42 

800 

125,000 

95,000 

65.0% 

18.0% 

225 

41 

900 

111,000 

84,000 

69.0% 

21.0% 

205 

38  . 

1,000 

100,000 

74,000 

71.0% 

24.5% 

185 

35 

1,100 

91,000 

66,000 

71.5% 

28.5% 

175 

33 

1,200 

84,000 

60,000 

72.0% 

31.5% 

160 

30 

1,300 

80,000 

54,000 

72.5% 

33.5% 

150 

29 

1,400 

75,000 

50,000 

72.5% 

35.0% 

150 

28 

[78] 


ALLOY  STEEL  IN  STOCK 


DEFINITIONS 

TENSILE  STRENGTH  —  Generally  expressed  in 
pounds  per  square  inch  and  as  such  represents  the 
greatest  load  a  bar,  whose  sectional  area  is  one 
square  inch  (1"  square,  }/<£'  x  2",  1.13"  round,  etc.), 
can  sustain  when  applied  gradually  in  direction  of 
its  length. 

ULTIMATE  STRENGTH — From  practical  standpoint 
same  as  Tensile  Strength. 

ELASTIC  LIMIT — A  term  usually  expressed  in 
pounds  per  square  inch.  If  this  stress  is  exceeded 
the  specimen  will  take  a  permanent  set;  for  example, 
a  spring  stressed  beyond  its  elastic  limit  will  not 
return  to  its  original  shape  when  load  is  released. 

YIELD  POINT — From  practical  standpoint  may  be 
considered  same  as  Elastic  Limit. 

SAFE  LOAD — The  stress  that  may  with  safety  be 
applied  to  any  part.  This  stress  must  never  exceed 
the  elastic  limit  and  is  usually  considerably  less  than 
this  figure. 

ELONGATION  OR  EXTENSION — The  amount  of 
stretch  in  a  test  specimen  produced  by  application 
of  stress  sufficient  to  cause  breakage  usually  ex- 
pressed as  a  percentage  of  a  2"  length,  marked  off 
before  stress  is  applied. 

REDUCTION  OF  AREA  OR  CONTRACTION  OF  AREA — 
Amount  of  reduction  in  cross  section  of  a  broken 
test  specimen  expressed  as  a  percent  of  the  original 
area. 


[79] 


JOSEPH        T.        RYERSON 


SON 


HEAT  TEMPERATURES  AND  COLORS 
FOR  HARDENING 


CENTIGRADE 
DEGBEES 

FAHRENHEIT 
DEGREES 

COLORS 

400 

752 

Red  Heat,  visible  in  the  dark 

474 

884 

Red  Heat,  visible  in  the  twilight 

525 

977 

Red  Heat,  visible  in  the  daylight 

581 

1077 

Red  Heat,  visible  in  the  sunlight 

700 

1292 

Dark  Red 

800 

1472 

Dull  Cherry  Red 

90D 

1652 

Cherry  Red 

1000 

1832 

Bright  Cherry  Red 

1100 

2012 

Orange  Red 

1200 

2192 

Orange  Yellow 

1300 

2372 

Yellow  White 

1400 

2552 

White  Welding  Heat 

HEATS  AND  TEMPER  COLORS  OF  STEEL 
PRODUCED  BY  HEAT 


CENTIGRADE 
DEGREES 

FAHRENHEIT 
DEGREES 

COLORS 

215.6 

420 

Very  Faint  Yellow 

221.11 

430 

Very  Pale  Yellow 

226.67 

440 

Light  Yellow 

232.23 

450 

Pale  Straw  Yellow 

237.78 

460 

Straw  Yellow 

243.34 

470 

Deep  Straw  Yellow 

248.9 

480 

Dark  Yellow 

254.45 

490 

Yellow  Brown 

260 

500 

Brown  Yellow 

265.56 

510 

Red  Brown 

271.11 

520 

Brown  Purple 

276.67 

530 

Light  Purple 

282.23 

540 

Full  Purple 

287.78 

550 

Dark  Purple 

293.34 

560 

Light  Blue 

298.9 

570 

Dark  Blue 

[80] 


ALLOY 


STEEL 


I     N 


STOCK 


FLASH  AND  FIRE  TESTS  OF  VARIOUS  OILS 


Name 


Flash  Degrees  Fire  Degrees 
Fahrenheit   Fahrenheit 


Corn 

Cottonseed 

Prime  Lard* 

No.  2  Lard** 

Boiled  Linseed 

Raw  Linseed 

Neatsf  oot 

Olive 

§'  t  Mineral  Oil  (25°  Beaume) 
Light  Mineral,  225%  Neatsf  oot. , 
Light  Mineral,  50%  Lard 
Light  Mineral,  50%  Lard , 
Light  Mineral,  75%  Lard 

Sperm  No.  1 

Sperm  No.  2 


480 
582 
/530\ 
\600j 
419 
378 
525 
439 
451 
410 
410 
410 
423 
441 
428 
486 


635 
644 

644 

468 
572 
644 
523 
541 
475 
471 
489 
513 
543 
518 
574 


*Acidity  not  to  exceed  2.0  per  cent,  determined  as  Oleic  Acid. 
**Acidity  not  to  exceed  15.0  per  cent,  determined  as  Oleic  Acid. 


MELTING  POINTS  OF  CHEMICAL  ELEMENTS 

Supplied  by  the  United  States  Bureau  of  Standards  in  Wash- 
ington from  latest  determinations.  These  values  are  the  most 
accurate  procurable  at  the  present  time.  The  values  originally 
determined  in  Centigrade  have  been  converted  directly  into 
Fahrenheit,  and  these  Fahrenheit  readings  should  not  be  taken 
as  correct  to  a  degree  at  the  higher  temperatures. 


Element 

Cent. 

Fahr. 

Element 

Cent. 

Fahr. 

Aluminum  

659 

1218 

Mercury  

—39 

—38 

Antimony      .  .  . 

630 

1166 

M  olybdenum 

2500? 

4532? 

850 

1562 

Nickel  

1452 

2646 

Bismuth  

271 

520 

Nitrogen 

—210 

—346 

Boron 

2200? 

3992? 

218 

360 

Calcium  

810 

1490 

Palladium 

1549 

2820 

Carbon 

3600? 

6510? 

+44 

+111 

Chlorine  

—102 

—151 

Platinum           . 

1755 

3191 

Chromium 

1520 

2768 

62 

144 

Cobalt  

1480 

2696 

Silicon 

1420 

2588 

Copper 

1083 

1981 

Silver 

960 

1761 

Gold 

1063 

1945 

97 

207 

Hydrogen  .... 

—259 

—434 

Sulphur  SI 

113 

236 

Iodine 

113 

236 

Tantalum 

2850? 

5160? 

Iridium  

2350? 

4262? 

Tin 

232 

450 

Iron 

1530 

2786 

1800? 

3272? 

Lead  

327 

621 

Tungsten 

3000? 

5430? 

Magnesium  

651 

1204 

Vanadium      .  . 

1720? 

3128? 

Manganese  

1260 

2300 

Zinc  

419 

787 

[.81] 


JOSEPH        T.        RYERSON 


SON 


TEMPERATURES 


CONVERSION  TABLES 


Degrees 
Centigrade  and  Fahrenheit 

Degrees 
Fahrenheit  and  Centigrade 

C 

F 

C 

F 

C 

F 

F 

C 

F 

C 

F 

C 

0 

32 

520 

968 

860 

1580 

32 

0 

1040 

560 

1720 

938 

100 

212 

530 

986 

870 

1598 

212 

100 

1060 

571 

1740 

949 

200 

392 

540 

1004 

880 

1616 

400 

204 

1080 

582 

1760 

960 

210 

410 

550 

1022 

890 

1634 

420 

216 

1100 

593 

1780 

971 

220 

428 

560 

1040 

900 

1652 

440 

227 

1120 

604 

1800 

982 

230 

446 

570 

1058 

910 

1670 

460 

238 

1140 

615 

1820 

993 

240 

464 

580 

1076 

920 

1688 

480 

249 

1160 

626 

1840 

1004 

250 

482 

590 

1094 

930 

1706 

500 

260 

1180 

637 

1860 

1015 

260 

500 

600 

1112 

940 

1724 

520 

271 

1200 

648 

1880 

1026 

270 

518 

610 

1130 

950 

1742 

540 

282 

1220 

659 

1900 

1038 

280 

536 

620 

1148 

960 

1760 

560 

293 

1240 

670 

1920 

1049 

290 

554 

630 

1166 

970 

1778 

580 

305 

1260 

681 

1940 

1060 

300 

572 

640 

1184 

980 

1796 

600 

316 

1280 

693 

1960 

1071 

310 

590 

650 

1202 

990 

1814 

620 

327 

1300 

705 

1980 

1082 

320 

608 

660 

1220 

1000 

1832 

640 

338 

1320 

716 

2000 

1093 

330 

626 

670 

1238 

1010 

1850 

660 

349 

1340 

727 

2020 

1105 

340 

644 

680 

1256 

1020 

1868 

680 

360 

1360 

738 

2040 

1116 

350 

662 

690 

1274 

1030 

1886 

700 

371 

1380 

749 

2060 

1127 

360 

680 

700 

1292 

1040 

1904 

720 

382 

1400 

760 

2080 

1138 

370 

698 

710 

1310 

1050 

1922 

740 

393 

1420 

771 

2100 

1149 

380 

716 

720 

1328 

1060 

1940 

760 

405 

1440 

782 

2120 

1160 

390 

734 

730 

1346 

1070 

1958 

780 

416 

1460 

793 

2140 

1171 

400 

752 

740 

1364 

1080 

1976 

800 

427 

1480 

804 

2160 

1182 

410 

770 

750 

1382 

1090 

1994 

820 

438 

1500 

816 

2180 

1193 

420 

788 

760 

1400 

1100 

2012 

840 

449 

1520 

827 

2200 

1204 

430 

806 

770 

1418 

1110 

2030 

860 

460 

1540 

838 

2220 

1216 

440 

824 

780 

1436 

1120 

2048 

880 

471 

1560 

849 

2240 

1227 

450 

842 

790 

1454 

1130 

2066 

900 

482 

1580 

860 

2260 

1238 

460 

860 

800 

1472 

1140 

2084 

920 

493 

1600 

871 

2280 

1249 

470 

878 

810 

1490 

1150 

2102 

940 

504 

1620 

882 

2300 

1260 

480 

896 

820 

1508 

1160 

2120 

960 

516 

1640 

893 

2320 

1271 

490 

914 

830 

1526 

1170 

2138 

980 

527 

1660 

904 

2340 

1283 

500 

932 

840 

1544 

1180 

2156 

1000 

538 

1680 

915 

2360 

1294 

510 

950 

850 

1562 

1190 

2174 

1020 

549 

1700 

927 

2380 

1305 

RULES  FOR  CONVERSION 

To  change  Centigrade  to  Fahrenheit,  multiply  by  9  and  divide 
by  5,  add  32.  Result  is  equivalent  Fahrenheit  temperature. 

To  change  Fahrenheit  to  Centigrade,  subtract  32,  multiply 
remainder  by  5  and  divide  by  9.  Result  is  equivalent  Centigrade 
temperature. 


[82] 


AL 


o 

fc 


LOY          STEEL          IN          STOCK 

O^OOCM      ooeooj-^      ouseot^     ooosc 
icio-*-*      (MT-CCOOO      r-io<MOJ      coeor 


3 


2§?2ico       Jo£c$< 

t>-  ic  co  o      r>-  ^#  I-H  < 

co^us      uscitx 


•**<  Tjl  1C  »O        ?J 


<M  (MCOCO 


)Ort<        OO<M  COO 
«  <M  CO        Q  10  0?  rt< 


I-H  cq  <M      e<»coeo  •* 


^f         ^— *  OO  CO  CO         *-H  c 


)U5        OU3 


iO  O  < 


§s  o 


'i-H  CO         U5t~< 


i-H         T^  T-*  r-<  i— 4        C<l  C^  C<I  CO         CO  ^*  *C  CO        CO  t^- O5  O 


00  O5O 


C^l  CO  1C 

88S 


>  •**<  O<M  T*ICO 

>i-H  CO  1C  ^t<CO 

O  tt<^^  OO 

iif5       COlr-OOO  •-< 


t— CO -^t*  i— t         OO  1C  C3  Oi         i-H  CO  CO  OO        O  CO  1 
COt^OOO        ^-ICOICCO         ^-(ICOSCO        OOtNK 

TH  1-*  T-t  T-(   T-t  <M  (M  IM  CO  CO  •*  I 


jss  s^§: 


)  CO  CO  ^         1C  CO  CO  1>-         C5  f^  CO  » 


t^CCCOUS         IC-^CCCM        -H  < 

cncot^i-H      icost^us      co< 


I(MCO        -*-*iO!C 


C<ICOC33»-H         C<l^t*lCCO         rHT^l--O         COlCCOO 


(MCOr-110         OT*ICOCO         005 
t^O-^t^          r-CT*(T-COO          IC^H 


(M  <M(M  IM 


ggg 


[83] 


JOSEPH        T.        RYERSON 


SON 


WEIGHT  OF  ROUND  AND  SQUARE  STEEL 
PER  LINEAL  INCH 


Size 

Round 

Square 

Size 

Round 

Square 

Size 

Round 

Square 

0 

.00 

.0000 

0 

2.01 

2.55 

0 

8.03 

10.2 

1-16 

.00 

.0011 

1-16 

2.09 

2.658 

1-16 

8.20 

10.416 

1-8 

.00 

.0044 

1-8 

2.18 

2.767 

1-8 

8.37 

10.633 

3-16 

.00 

.0995 

3-16 

2.27 

2.88 

3-16 

8.54 

10,850 

1-4 

.01 

.0177 

1-4 

2.36 

2.993 

1-4 

8.71 

11.067 

5-16 

.02 

.0278 

5-16 

2.45 

3.110 

5-16 

8.89 

11.292 

3-8 

.03 

.0398 

3-8 

2.54 

3.227 

3-8 

9.07 

11.517 

07-16 

.04 

.0542 

0    7-16 

2.64 

3.348 

R    7-16 

9.25 

11.742 

1-2 

.06 

.0708 

0    i_2 

2.73 

3.471 

0    i_2 

9.43 

11.967 

9-16 

.07 

.0897 

9-16 

2.83 

3.595 

9-16 

9.61 

12.208 

5-8 

.09 

.1107 

5-8 

2.93 

3.723 

5-8 

9.79 

12.433 

11-16 

.11 

.1341 

11-16 

3.03 

3.853 

11-16 

9.98 

12.675 

3-4 

.13 

.1580 

3-4 

3.14 

3.985 

3-4 

10.16 

12.908 

13-16 

.15 

.1870 

13-16 

3.24 

4.118 

13-16 

10.35 

13.15 

7-8 

.17 

.2166 

7-8 

3.35 

4.254 

7-8 

10.54 

13.4 

15-16 

.20 

.2490 

15-16 

3.46 

4.392 

15-16 

10.74 

13.633 

0 

.22 

.2833 

0 

3.57 

4.533 

0 

10.93 

13.883 

1-16 

.25 

.3209 

1-16 

3.68 

4.776 

1-16 

11.13 

14.133 

1-8 

.28 

.3585 

1-8 

3.80 

4.821 

1-8 

11.33 

14.383 

3-16 

.31 

.3995 

3-16 

3.91 

4.968 

3-16 

11.52 

14.633 

1-4 

.35 

.4426 

1-4 

4.03 

5.117 

1-4 

11.73 

14.892 

5-16 

.38 

.4880 

5-16 

4.14 

5.27 

5-16 

11.93 

15.15 

3-8 

.42 

.5356 

3-8 

4.27 

5.423 

3-8 

12.13 

15.409 

1     7-16 

.46 

.5855 

A    7-16 

4.39 

5.579 

7    7-16 

12.34 

15.675 

1     1-2 

.50 

.6375 

*    1-2 

4.52 

5.737 

'     1-2 

12.55 

15.947 

9-16 

.54 

.6917 

9-16 

4.64 

5.898 

9-16 

12.76 

16.208 

5-8 

.59 

.7481 

5-8 

4.77 

6.061 

5-8 

12.97 

16.475 

11-16 

.64 

.8068 

11-16 

4.90 

6.225 

11-16 

13.18 

16.743 

3-4 

.68 

.8675 

3-4 

5.03 

6.392 

3-4 

13.40 

17.017 

13-16 

.73 

.9308 

13-16 

5.17 

6.562 

13-16 

13.61 

17.300 

7-8 

.78 

.9958 

7-8 

5.30 

6.734 

7-8 

13.84 

17.567 

15-16 

.84 

1.063 

15-16 

5.44 

6.908 

15-16 

14.05 

17.85 

0 

.89 

.133 

0 

5.58 

7.083 

0 

14.28 

18.133 

1-16 

.95 

.2051 

1-16 

5.72 

7.262 

1-16 

14.50 

18.420 

1-8 

.01 

.279 

1-8 

5.86 

7.442 

1-8 

14.73 

18.708 

3-16 

.07 

.355 

3-16 

6.00 

7.624 

3-16 

14.95 

19. 

1-4 

.13 

.435 

1-4 

6.15 

7.81 

1-4 

15.18 

19.283 

5-16 

.19 

.515 

5-16 

6.30 

7.997 

5-16 

15.41 

19.575 

3-8 

.26 

.598 

3-8 

6.45 

8.186 

3-8 

15.65 

19.875 

0     7-16 
L     !_2 

.33 
.39 

.683 
.770 

C    7-16 
0    1-2 

6.60 
6.75 

8.375 
8.567 

87-16 
1-2 

15.88 
16.12 

20.167 
20.467 

9-16 

.46 

.860 

9-16 

6.90 

8.767 

9-16 

16.36 

20.775 

5-8 

.54 

.952 

5-8 

7.06 

8.967 

5.8 

16.60 

21.075 

11-16 

.61 

2.046 

11-16 

7.22 

9.167 

11-16 

16.83 

21.383 

3-4 

.69 

2.083 

3-4 

7.38 

9.367 

3-4 

17.08 

21.692 

13-16 

.76 

2.241 

13-16 

7.54 

9.575 

13-16 

17.32 

22.008 

7-8 

.84 

2.341 

7-8 

7.70 

9.783 

7-8 

17.57 

22.325 

15-16 

.92 

2.445 

15-16 

7.86 

9.992 

15-16 

17.82 

22.633 

-•     fe 


[84] 


ALLOY 


T    E    E    L 


I    N 


STOCK 


WEIGHT  OF  ROUND  AND  SQUARE  STEEL 
PER  LINEAL  INCH 


Size 

Round 

Square 

Size 

Round 

Square 

Size 

Round 

Square 

0 

18.07 

22.950 

0 

32.13 

40.800 

0 

50.19 

63.768 

1-16 

18.32 

23.270 

1-16 

32.46 

41.232 

1-16 

50.61 

64.291 

1-8 

18.58 

23.600 

1-8 

32.80 

41.664 

1-8 

51.03 

64.832 

3-16 

18.83 

23.917 

3-16 

33.13 

42.096 

3-16 

51.45 

65.366 

1-4 

19.09 

24.242 

1-4 

33.48 

42.528 

1-4 

51.87 

65.900 

5-16 

19.34 

24.575 

5-16 

33.81 

42.963 

5-16 

52.30 

66.436 

3-8 

19.61 

24.908 

3-8 

34.17 

43.400 

3-8 

52.73 

66.972 

97-16 
1-2 

19.87 
20.13 

25.233 
25.567 

107-16 
1*1-2 

34.51 
34.86 

43.833 
44.268 

1C  7-16 
10  1-2 

53.16 
53.59 

67.520 
68.068 

9-16 

20.40 

25.908 

9-16 

35.21 

44.718 

9-16 

54.02 

68.634 

5-8 

20.67 

26.25 

5-8 

35.56 

45.168 

5-8 

54.46 

69.200 

11-16 

20.93 

26.591 

11-16 

35.91 

45.618 

11-16 

54.89 

69.734 

3-4 

21.21 

26.933 

3-4 

36.27 

46.068 

3-4 

55.33 

70.268 

13-16 

21.48 

27.283 

13-16 

36.62 

46.518 

13-16 

55.77 

70.834 

7-8 

21.76 

27.633 

7-8 

36.98 

46.968 

7-8 

56.21 

71.400 

15-16 

22.03 

27.983 

15-16 

37.33 

47.418 

15-16 

56.66 

71.966 

0 

22.31 

28.333 

0 

37.70 

47.868 

0 

57.10 

72.533 

1-16 

-22.59 

28.683 

1-16 

38.06 

48.35 

1-16 

57.55 

73.102 

1-8 

22.87 

29.042 

1-8 

38.42 

48.832 

1-8 

57.99 

73.671 

3-16 

23.15 

29.408 

3-16 

38.79 

49.282 

3-16 

58.45 

74.251 

1—4 

23.44 

29.767 

1-4 

39.16 

49.732 

1-4 

58.90 

74.832 

5-16 

23.72 

30.133 

5-16 

39.53 

50.218 

5-16 

59.35 

75.416 

3-8 

24.01 

30.5 

3-8 

39.90 

50.704 

3-8 

59.81 

76.000 

in  7-16 

24.30 

30.867 

107-16 

40.28 

51.168 

•|g7-16 

60.27 

76.566 

•"1-2 

24.60 

31.242 

•3  1-2 

40.65 

51.632 

60.73 

77.132 

9-16 

24.89 

31.617 

9-16 

41.03 

52.116 

9-16 

61.19 

77.726 

5-8 

25.19 

31.983 

5-8 

41.41 

52.600 

5-8 

61.65 

78.316 

11-16 

25.48 

32.358 

11-16 

41.79 

53.100 

11-16 

62.11 

78.908 

3-4 

25.78 

32.741 

3-4 

42.17 

53.600 

3-4 

62.58 

79.500 

13-16 

26.08 

33.125 

13-16 

42.56 

54.066 

13-16 

63.05 

80.084 

7-8 

26.39 

33.508 

7-8 

42.94 

54.532 

7-8 

63.52 

80.668 

15-16 

26.68 

33.900 

15-16 

43.33 

55.032 

15-16 

63.99 

81.275 

0 

27.00 

34.283 

0 

43.72 

55.532 

0 

64.46 

81.883 

1-16 

27.30 

34.675 

1-16 

44.11 

56.032 

1-16 

64.94 

82.481 

1-8 

27.61 

35.075 

1-8 

44.50 

56.532 

1-8 

65.41 

83.080 

3-16 

27.92 

35.458 

3-16 

44.90 

57.032 

3-16 

65.89 

83.690 

1-4 

28.24 

35.858 

1-4 

45.29 

57.532 

1-4 

66.37 

84.300 

5-16 

28.54 

36.258 

5-16 

45.69 

58.032 

5-16 

66.85 

84.919 

3-8 

28.87 

36.658 

3-8 

46.09 

58.532 

3-8 

67.34 

85.532 

11™ 

29.19 
29.50 

37.067 
37.467 

U7-16 
1-2 

46.49 
46.90 

59.058 
59.568 

n7-16 
1-2 

67.82 
68.31 

86.150 
86.768 

9-16 

29.83 

37.875 

9-16 

47.30 

60.084 

9-16 

68.80 

87.400 

5-8 

30.15 

38.291 

5-8 

47.71 

60.600 

5-8 

69.29 

88.032 

11-16 

30.47 

38.700 

11-16 

48.12 

61.118 

11-16 

69.78 

88.666 

3-4 

30.80 

39.117 

3-4 

48.53 

61.636 

3-4 

70.28 

89.300 

13-16 

31.12 

39.533 

13-16 

48.94 

62.168 

13-16 

70.77 

89.924 

7-8 

31.46 

39.875 

7-8 

49.35 

62.700 

7-8 

71.27 

90.548 

15-16 

31.79 

40.375 

15-16 

49.77 

63.234 

15-16 

71.77 

91.174 

[85] 


JOSEPH        T.        RYERSON 


SON 


WEIGHT  OF  ROUND  AND  SQUARE  STEEL 
PER  LINEAL  INCH 


Size 

Round 

Square 

Size 

Round 

Square 

Size 

Round 

Square 

0 

72.27 

91.800 

0 

98.37 

124.968 

0 

128.48 

163.2 

1-16 

72.77 

92.439 

1-16 

98.94 

125.718 

1-16 

129.17 

164.064 

1-8 

73.28 

93.079 

1-8 

99.54 

126.468 

1-8 

129.82 

164.928 

3-16 

73.78 

93.739 

3-16 

100.13 

127.200 

3-16 

130.49 

165.792 

1-4 

74.29 

94.400 

1-4 

100.72 

127.932 

1-4 

131.17 

166.656 

5-16 

74.80 

95.034 

5-16 

101.32 

128.682 

5-16 

131.85 

167.520 

3-8 

75.31 

95.668 

3-8 

101.91 

129.432 

3-8 

132.53 

168.384 

1  ft7"16 
10  1-2 

75.82 
76.34 

96.318 
96.968 

M7-16 
1-2 

102.51 
103.11 

130.198 
130.964 

OA7-16 
^1-2 

133.20 
133.89 

169.248 
170.112 

9-16 

76.86 

97.634 

9-16 

103.71 

131.732 

9-16 

134.57 

170.982 

5-8 

77.38 

98.300 

5-4 

104.31 

132.500 

5-8 

135.26 

171.852 

11-16 

77.90 

98.966 

11-16 

104.91 

133.266 

11-16 

135.94 

172.726 

3-4 

78.42 

99.632 

3-4 

105.52 

134.032 

3-4 

136.63 

173.600 

13-16 

78.94 

100.282 

13-16 

106.13 

134.816 

13-16 

137.  3p 

174.466 

7-8 

79.47 

100.932 

7-8 

106.73 

135.600 

7-8 

138.02 

175.332 

15-16 

79.99 

101.600 

15-16 

107.35 

136.366 

15-16 

138.71 

176.202 

0 

80.52 

102.268 

0 

107.96 

137.132 

25 

139.41 

177.072 

1-16 

81.05 

102.950 

1-16 

108.57 

137.916 

. 

1-8 

81.59 

103.632 

1-8 

109.19 

138.700 

3-16 

82.12 

104.316 

3-16 

109.81 

139.5 

1-4 

82.66 

105.000 

1-4 

110.43 

140.300 

5-16 

83.19 

105.682 

5-16 

111.05 

141.066 

3-8 

83.73 

106.364 

3-8 

111.67 

141.832 

1  07-16 
13  1-2 

84.27 
84.82 

107.048 
107.732 

007-16 
"1-2 

112.29 
112.92 

142.632 
143.432 

9-16 

85.36 

108.432 

9-16 

113.55 

144.232 

5-8 

85.91 

109.132 

5-8 

114.18 

145.032 

11-16 

86.45 

109.832 

11-16 

114.81 

145.832 

3-4 

87.00 

110.532 

3-4 

115.44 

146.632 

13-16 

87.56 

111.232 

13-16 

116.08 

147.450 

7-8 

88.11 

111.932 

7-8 

116.72 

148.268 

15-16 

88.66 

112.632 

15-16 

117.35 

149.068 

0 

89.22 

113.333 

0 

118.00 

149.868 

1-16 

89.78 

114.032 

1-16 

118.64 

150.684 

1-8 

90.34 

114.732 

1-8 

119.28 

151.500 

3-16 

90.90 

115.450 

3-16 

119.93 

152.332 

1-4 

91.47 

116.168 

1-4 

120.57 

153.164 

5-16 

92.03 

116.900 

5-16 

121.22 

153.98 

3-8 

92.60 

117.632 

3-8 

121.87 

154.800 

M7-16 
1-2 

93.17 
93.74 

118.350 
119.068 

007-16 
"1-2 

122.52 
123.18 

155.63 
156.46 

9-16 

94.3 

119.800 

9-16 

123.84 

157.30 

5-8 

94.88 

120.53 

5-8 

124.50 

158.13 

11-1 

95.46 

121.26 

11-16 

125.1 

158.81 

3-4 

96.04 

122.00 

3-4 

125.8 

159.50 

13-1 

96.62 

122.73 

13-1 

126.4 

160.50 

7-8 

97.  2C 

123.46 

7-8 

127.1 

161.50 

15-1 

97.78 

124.21 

15-1 

127.8 

162.35 

[86] 


ALLOY 


T    E     E     L 


I     N 


TOOK 


BAB  STEEL 
WEIGHT  PER  LINEAL  FOOT  IN  POUNDS 


Size 

Round 

Square 

Hexagon 

Octagon 

K? 

.04 

.05 

.05 

.04 

A' 

.09 

.12 

.10 

.10 

Yt 

.17 

.21 

.19 

.18 

A 

.26 

.33 

.29 

.28 

H 

.38 

.48 

.42 

.40 

ft 

.51 

.65 

.57 

.54 

H 

.67 

.85 

.75 

.70 

.85 

1.08 

.94 

.89 

5,g 

1.04 

1.33 

1.17 

1.10 

H 

1.27 

1.61 

1.41 

1.33 

s/ 

1.50 

1.92 

1.68 

1.58 

14 

1.76 

2.24 

1.97 

1.83 

H 

2.04 

2.60 

2.29 

2.16 

IS 

2.35 

3.06 

2.62 

2.48 

» 

2.67 

3.40 

2.99 

2.82 

IxC 

3.38 

4.30 

3.78 

3.56 

54 

4.17 

5.31 

4.66 

4.40 

3% 

5.05 

6.43 

5.65 

5.32 

J-i 

6.01 

7.65 

6.72 

6.34 

B^ 

7.05 

8.98 

7.89 

7.32 

«/ 

8.18 

10.40 

9.14 

8.64 

7^ 

9.38 

11.90 

10.50 

9.92 

2" 

10.71 

13.60 

11.95 

11.28 

2i% 

12.05 

15.40 

13.49 

12.71 

2K 

13.60 

17.20 

15.12 

14.24 

2^8 

15.10 

19.20 

16.85 

15.88 

2V£ 

16.68 

21.20 

18.66 

17.65 

25/£ 

18.39 

23.50 

20.58 

19.45 

23/ 

20.18 

25.70 

22.59 

21.28 

t£ 

22.06 

28.20 

24.69 

23.28 

24.10 

30.60 

26.88 

25.36 

i 

26.12 

33.13 

29.16 

27.50 

3J4 

28.30 

35.90 

31.55 

29.28 

gax 

30.45 

38.64 

34.00 

32.10 

22 

32.70 

41.60 

36.59 

34.56 

JJKZ 

35.20 

44.57 

39.24 

37.05 

33/ 

37.54 

47.80 

42.00 

39.68 

4' 

42.72 

54.40 

47.78 

45.12 

4/4 

48.30 

61.40 

53.95 

50.84 

4^ 

54.60 

68.90 

60.48 

56.96 

60.30 

76.70 

67.39 

63.52 

5' 

66.80 

85.00 

74.66 

70.60 

73.60 

93.70 

82.32 

77.80 

5V6 

80.80 

102.80 

90.36 

85.15 

5% 

88.30 

112.40 

98.76 

93.12 

6i  ' 

96.10 

122.40 

107.52 

101.45 

113.20 

143.60 

126.20 

117.12 

7* 

130.80 

166.40 

146.36 

138.24 

8' 

170.88 

217.60 

191.12 

180.48 

9' 

218.40 

275.60 

241.92 

227.84 

10' 

267.20 

340.00 

298.64 

282.40 

11* 

323.00 

411.20 

361.44 

340.60 

12' 

384.00 

489.60 

470.08 

405.80 

For  High  Speed  add  12  per  cent  to  above  weights. 


[87] 


JOSEPH        T.        RYERSON        &        SON 


O  O 

cooiO/coo5cocoo5coca 
10  «>     to  ic  oo  rH  eo  c    o» 


O5  00  00 
t^i-iiO 


CO 
(M 


O  O  O  OO 


[88] 


ALLOY  STEEL  IN  STOCK 


90  £3  •£  00  ®  «  O  £3  go  O  IQ  .0  <M  co  o  oo  co  o 

COOCOCOOCOi>'OcOt>-O^frll>«OTfrtOt>-'— I 

cOOOO<M*OOOOTt<iOOOOC^iOOOOiOOQ 
<N  CO  lO  CO  t>.  00  O"i— i  <NCO»Ocoi>OOO<NiOO 

oooooooooooooooooo 

Ot^^r-*OOtO(NcoOOO 

i  co  »oi>  o-^  o 

<N  C^J  C^  CO  CO  ••* 

]8$&88% 

cc??rHO5co??QQ?oooooooo»O'-^o 

O  CO  l>-  Oi  O  (N 

"^  (NO5 
1C 

K 

ii— !00-<*r-<l>.CO&'cO<MO5iOC^-^l>CO 
(MCOCO-^iO4OCOl>t>.OOOOO5Oi— i(M»O 


SOCO 
CO»—  I 


[89] 


JOSEPH        T    . 


R    Y 


R    S    O    N 


SON 


TYPICAL  TENSILE  STRENGTHS  OF  HEAT  TREATED 
STEEL  OF  DIFFERENT  CARBON  CONTENT 


Carbon 
per  Cent. 

Approximate  Tensile  Strength  in  Lbs. 
per  Square  Inch. 

.05to  .10 

47,040  to   60,480 

.lOto  .15 

53,760  to   64,960 

.15  to  .20 

60,480  to   71,680 

.20  to  .25 

64,690  to   76,160 

.25  to  .30 

67,200  to   78,400 

.30  to  .35 

69,440  to   82,800 

.35  to  .40 

78,400  to   91,840 

.40  to  .45 

87,360  to  100,800 

.45  to  .50 

96,320  to  107,520 

.50to  .55 

105,280  to  118,920 

.55  to  .60 

112,000  to  123,200 

.60  to  .65 

116,480  to  127,680 

.65  to  .70 

123,200  to  134,400 

.70  to  .75 

129,920  to  138,880 

.75  to  .80 

134,400  to  143,360 

.80  to  .85 

136,640  to  145,600 

.85  to  .90 

141,120  to  150,800 

WORKING  TEMPERATURES  FOR  CARBON  STEELS 


NAME 

Carbon 
Content 

Appro*. 
Critical 
Temp. 

Forging 
Temp. 

Quenching 
Temp. 

Machinery 

0  25 

1475 

1650 

1525-1575 

Machinery  
Machinery. 

0.35 
0  45 

1395 
1385 

1650 
1650 

1450-1500 
1435-1485 

Crucible  Machy  . 
Crucible  Machy  . 
Tool  Steel  
Tool  Steel  

0  50 
0  55 
0  60 
0  70 

1380 
1375 
1365 
1355 

1625 
1625 
1600 
1600 

1430-1480 
1425-1475 
1400-1460 
1400-1460 

Tool  Steel  . 

0  80 

1350 

1600 

1375-1450 

Tool  Steel  
Tool  Steel 

0.90 
1  00 

1350 
1350 

1575 
1575 

1375-1450 
1375-1450 

Tool  Steel  

1.10 

1350 

1500 

1375-1430 

Tool  Steel  

1.20 

1350 

1500 

1375-1420 

Tool  Steel.  

1  30 

1350 

1500 

1375-1420 

[90] 


ALLOY 


T    E    E    L 


I     N 


STOCK 


MILLIMETER  EQUIVALENTS  IN  INCHES 


Millimeters 

Inches 

Millimeters 

Inches 

Millimeters 

Inches 

10 

_ 

.0039 

29 

m 

1 

.1417 

66 

= 

2 

5984 

20 

= 

.0079 

30 

= 

1 

.1811 

67 

= 

2 

6378 

30 

= 

.0118 

31 

= 

1 

.2205 

68 

= 

2 

6772 

40 

= 

.0157 

32 

= 

1 

.2599 

69 

= 

2 

7165 

50 

= 

.0197 

33 

= 

1 

.2992 

70 

= 

2 

7559 

00 

= 

.0236 

34 

= 

1 

.3386 

71 

= 

2 

7953 

70 

M 

.0276 

35 

= 

1 

.3780 

72 

= 

2 

8346 

80 

M 

.0315 

36 

= 

.4173 

73 

= 

2 

8740 

90 

M 

.0354 

37 

= 

.4567 

74 

m 

2 

9134 

1 

= 

.0394 

38 

= 

.4961 

75 

= 

2 

9528 

2 

= 

.0787 

39 

= 

.5354 

76 

=s 

2 

9921 

3 

= 

.1181 

40 

= 

.5748 

77 

= 

3 

0315 

4 

= 

.1575 

41 

= 

.6142 

78 

= 

3 

0/709 

5 

= 

.1969 

42 

= 

.6536 

79 

= 

3 

1102 

6 

= 

.2362 

43 

= 

.6929 

80 

= 

3 

1496 

7 

= 

.2756 

44 

= 

.7323 

81 

= 

3 

1890 

8 

— 

.3150 

45 

= 

.7717 

82 

=  3.2283 

9 

a- 

.3543 

46 

— 

.8110 

83 

= 

3 

2677 

10 

tp 

.3937 

47 

= 

.8504 

84 

= 

3 

3071 

11 

= 

.4331 

48 

= 

1 

.8988 

85 

= 

3 

3465 

12 

. 

.4724 

49 

= 

1 

.9291 

86 

= 

3 

3858 

13 

= 

.5118 

50 

= 

1 

.9685 

87 

= 

3 

4252 

14 

= 

.5512 

51 

= 

2 

.0079 

88 

= 

3 

4646 

15 

.• 

.5906 

52 

= 

2 

.0472 

89 

= 

3 

5039 

16 

— 

.6299 

53 

m 

2 

.0866 

90 

= 

3 

5433 

17 

M 

.6693 

54 

— 

2 

.1260 

91 

= 

3 

5827 

18 

• 

.7087 

55 

= 

2 

.1654 

92 

= 

3 

6221 

19 

= 

.7480 

56 

=. 

2 

.2047 

93 

= 

3 

6614 

20 

= 

.7874 

57 

= 

2 

.2441 

94 

= 

3 

7008 

21 

= 

.8268 

58 

= 

2 

.2835 

95 

= 

3 

7402 

22 

= 

.8661 

59 

= 

2 

.3228 

96 

=• 

3 

7795 

23 

= 

.9055 

60 

= 

2 

.3622 

97 

M 

3 

8189 

24 

Mfc 

.9449 

61 

= 

2 

.4016 

98 

=  3.8583 

25 

= 

.9843 

62 

= 

2 

.4409 

99 

=  3.8976 

26 

m 

1.0236 

63 

M 

2 

.4803 

100 

= 

3 

9370 

27 



1  0630 

64 

_ 

2 

.5197 

28 

= 

1  .  1024 

65 

= 

2 

.5591 

[91] 


JOSEPH        T.        RYER80N        &       SON 


TYPICAL  FORMULA  FOR  CARBONIZING 


CHBOME  NICKEL  STEEL  SAE  3120: 

Carbonise  at  1625  to  1700  degrees. 

Cool  in  box  and  remove. 

Re-heat  to  1550  to  1600  degrees. 

Quench  in  oil. 

Re-heat  to  1300  to  1400  degrees. 

Quench  in  oil  or  water. 

Draw  to  from  300  to  450  degrees. 

3^%  NICKEL  STEEL  SAB  2320: 

Carbonize  at  1625  to  1675. 

Cool  in  boxes  and  remove. 

Re-heat  to  1550  to  1575. 

Quench  in  oil. 

Re-heat  to  1300  to  1400  degrees. 

Quench  in  oil  or  water. 

Draw  to  from  300  to  450  degrees. 

CARBON  STEEL  SAE  1020: 

Carbonize  at  1650  to  1700. 
Cool  in  boxes  and  remove. 
Re-heat  to  1550  to  1600. 
Quench  in  oil. 
Re-heat  to  1400  to  1450. 
Quench  in  oil  or  water. 
Draw  to  about  400  degrees. 

The  above  formulae  are  approximate  and  will  be  subject  to 
change  according  to  the  size  of  pieces  being  carbonized  and  also 
the  depth  of  penetration  required.  The  final  drawing  tem- 
perature will  have  to  be  modified,  depending  on  the  degree  of 
hardness  required  in  the  finished  article. 

As  in  all  other  heat  treating  operations,  definite  formulae  for 
carbonizing  can  best  be  obtained  by  actual  experiment  and  a 
little  time  and  money  spent  in  this  way  will  be  well  invested 
inasmuch  as  it  will  save  the  possible  damaging  of  valuable  work. 


[92] 


ALLOY 


STEEL 


I    N 


STOCK 


a 


II 


ggg 


sss 


888888 

333  333 


333 


1 


II 


Hg 


§§§§§§ 

eoecco  eocoeo 


eoeoeo  eoeoeo 

333  333 


cccoeo  eococo 


333  333 


333  333 

O  1C  >O    OlOO 

-H r-icq  eceoTti 


33 


(M 


»  » 
1-1- 

33 


l 


33 
§§ 


1 

J3 


33 


[93] 


JOSEPH        T 


RYER8ON 


SON 


l! 


SJ2J2 


g 

333   3 


la 


s 


5S  S 


333   3 


823  1 


•3* 

'*V 

l§ 

ll 
Is 


oS 
Id 

<T  g 


I 


Minimum 
Maximu 


§ 

w'*3 

-1* 


222    222    22 
o 


000      000      00 


333    33 


sss 


ss 


S2S 


00  00  00  00  §  00  00  5 

o 

333  333  S3 

§g§  SSS  §g 


.  =  •- 

-»   — 


333    333    33 


[94] 


ALLOY 


STEEL          IN  STOCK 

5O       OOO       OOO 

S<0        (DfOTl        ^H^H—I 


§ 


333    333    333    333 

»0»OU5       «0i«0       000       000 

•*•***      »*T»<a>      ososos      ooco 


888 


§§§  sss 


an 
m 


Min 
M 


.H^^H      ^H^HW      <M<MO»      coeoeo      eocoeo 


333  333  333  333 
§§§  §§S  SSS  SEE  888 


1J 

1J 


ill  sis  sss  sss  sss 


w 

£* 


sss  sss  sss  sss  sss 

o 


555 


§£ 

a  I 

i1 


§§§  SSS  §§§  EE^  §§§ 

333  333  333  333  333 

000  000  000  U3»«iO  000 

«o«c«o  i«»oco  coeoeo  '*'*'*  cococo 


sss 


333    333    333    333    333 
J2°i8    cocoJS    8e?5    2co5    S8co 


O  O        USi«  O 

«*c  »O         T-I  03  >O 

eocoeo      coeoeo      coeoeo 


has 


[95] 


THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 


AN     INITIAL     FINE     OF     25     CENTS 

WILL  BE  ASSESSED  FOR  FAILURE  TO  RETURN 
THIS  BOOK  ON  THE  DATE  DUE.  THE  PENALTY 
WILL  INCREASE  TO  5O  CENTS  ON  THE  FOURTH 
DAY  AND  TO  $1.OO  ON  THE  SEVENTH  DAY 
OVERDUE. 


APR  12    1933 


OCT  21   1933 


V** 


'57T8 


RECTO 


APR 


1319SI 


REC'D  Z.D 

MAR  10  1959 


YB        1 62 


49448? 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


